Version 3 of the National Center for Atmospheric Research Community Climate Model is used to investigate the response of terrestrial carbon exchange and atmospheric CO{sub 2} concentrations to sea surface temperature (SST) anomalies associated with the El Nino phenomenon. Air-sea exchange of CO{sub 2} is not included. During El Nino episodes, atmospheric CO{sub 2} concentrations are observed to rise anomalously even though CO{sub 2} outgassing is reduced in the eastern equatorial Pacific due to the cessation of upwelling. Atmospheric carbon isotope data point to a larger terrestrial carbon release as being responsible. The reasons for such a terrestrial response are examined by comparing a control run with prescribed, seasonally varying, climatological SSTs to an ensemble of integrations employing observed SST fields from the strong El Nino event of 1982-83. The model captures the main features of the El Nino induced meteorological anomalies, including the shifts in tropical rainfall patterns that are of particular importance in driving the carbon cycle changes. Most of the regions that exhibit a clear El Nino signal in the simulation possess well documented links to El Nino in the observational record, Examples include northeastern South America, India, Indonesia, southeastern Africa, Ecuador and northern Peru, and parts of southeastern South America. The combined perturbation of the net carbon flux in these areas involves a release of CO{sub 2} to the atmosphere totalling 7 GtC during the 1982-83 El Nino event. Atmospheric CO{sub 2} rises by about 3 ppmv as a result which is more than sufficient to explain the observed variations. The exaggerated response is indicative of the strong sensitivity of the model carbon routines to climate fluctuations. It is argued that the release of CO{sub 2} from terrestrial systems is fundamentally related to the overall shift of precipitation from land areas to the oceans caused by the El NinoSSTforcing. Since the SSTforcing

Two distinct roles of the Atlantic sea surface temperatures (SSTs), namely, the North Tropical Atlantic (NTA) SST and the Atlantic Nino, on the El Nino-Southern Oscillation (ENSO) variability are investigated using the observational data from 1980 to 2010 and coupled model experiments. It appears that the NTA SST and the Atlantic Nino can be used as two independent predictors for predicting the development of ENSO events in the following season. Furthermore, they are likely to be linked to different types of El Nino events. Specifically, the NTA SST cooling during February, March, and April contributes to the central Pacific warming at the subsequent winter season, while the negative Atlantic Nino event during June, July, and August contributes to enhancing the eastern Pacific warming. The coupled model experiments support these results. With the aid of a lagged inverse relationship, the statistical forecast using two Atlantic indices can successfully predict various ENSO indices.

In this paper, we have identified three principal modes of summertime rainfall variability over China and global sea surface temperature (SST) for the period 1955-1998. Using these modes, we have assessed the impact of the El Nino/La Nina on major drought and flood occurrence over China during 1997-1998. The first mode can be identified with the growth phase of El Nino superimposed on a linear warming trend since the mid-1950s. This mode strongly influences rainfall over northern China. The second mode comprises of a quasi-biennial tendency manifested in alternate wet and dry years over the Yangtze River Valley (YRV) of central China. The third mode is dominated by a quasi-decadal oscillation in eastern China between the Yangtze River and the Yellow River. Using a mode-by-mode reconstruction, we evaluate the impacts of the various principal modes on the 1997 and 1998 observed rainfall anomaly. We find that the severe drought in northern China, and to a lesser degree the flood in southern China, in 1997 is likely a result of the influence of anomalous SSTforcing during the growth phase of the El Nino. In addition, rainfall in southern China may be influenced by the decadal or long-term SST variability. The severe flood over the Yangtze River Valley in 1998 is associated with the biennial tendency of basin scale SST during the transition from El Nino to La Nina in 1997-98. Additionally, the observed prolonged drought over northern China and increasing flooding over the YRV since the 1950s may be associated with a long-term warming trend in the tropical Indian and western Pacific ocean. During 1997, the El NinoSST exacerbated the drought situation over northern China. In 1998, the drought appeared to get temporary relief from the La Nina anomalous SSTforcing.

Volcanic aerosols formed in the stratosphere after strong explosive eruptions influence Earth\\'s radiative balance, affecting atmospheric and oceanic temperatures and circulation. It was observed that the recent volcanic eruptions frequently occurred in El Nino years. Analysis of the paleo data confirms that the probability of a sequent El Nino occurrence after the eruption increases. To better understand the physical mechanism of this interaction we employed ocean-atmosphere coupled climate model CM2.1, developed in the Geophysical Fluid Dynamics Laboratory, and conducted a series of numerical experiments using initial conditions with different El Nino Southern Oscillation (ENSO) strengths forced by volcanic eruptions of different magnitudes, Pinatubo of June 1991 and Tambora of April 1815: (i) strong ENSO/Pinatubo, (ii) weak ENSO/Pinatubo, (iii) strong ENSO/Tambora. The amount of ejected material from the Tambora eruption was about three times greater than that of the Pinatubo eruption. The initial conditions with El Nino were sampled from the CM2.1 long control run. Our simulations show the enhancement of El Nino in the second year after an eruption. We found that the spatial-temporal structure of model responses is sensitive to both the magnitude of an eruption and the strength of El Nino. We analyzed the ocean dynamic in the tropical Pacific for all cases to uncover the physical mechanism, resulting in the enhanced and/or prolonged El Nino.

Warm pool El Nino (WPEN) events are characterized by positive sea surface temperature (SST) anomalies in the central equatorial Pacific. Under present-day climate conditions, WPEN events generate poleward propagating wavetrains and enhance midlatitude planetary wave activity, weakening the stratospheric polar vortices. The late 21st century extratropical atmospheric response to WPEN events is investigated using the Goddard Earth Observing System Chemistry-Climate Model (GEOSCCM), version 2. GEOSCCM simulations are forced by projected late 21st century concentrations of greenhouse gases (GHGs) and ozone-depleting substances (ODSs) and by SSTs and sea ice concentrations from an existing ocean-atmosphere simulation. Despite known ocean-atmosphere model biases, the prescribed SST fields represent a best estimate of the structure of late 21st century WPEN events. The future Arctic vortex response is qualitatively similar to that observed in recent decades but is weaker in late winter. This response reflects the weaker SSTforcing in the Nino 3.4 region and subsequently weaker Northern Hemisphere tropospheric teleconnections. The Antarctic stratosphere does not respond to WPEN events in a future climate, reflecting a change in tropospheric teleconnections: The meridional wavetrain weakens while a more zonal wavetrain originates near Australia. Sensitivity simulations show that a strong poleward wavetrain response to WPEN requires a strengthening and southeastward extension of the South Pacific Convergence Zone; this feature is not captured by the late 21st century modeled SSTs. Expected future increases in GHGs and decreases in ODSs do not affect the polar stratospheric responses to WPEN.

The present study suggests that the off-equatorial North Atlantic (NATL) SST warming plays a significant role in modulating El Niño teleconnection and its impact on the North Atlantic and European regions. The El Niño events accompanied by NATL SST warming exhibit south-north dipole pattern over the Western Europe to Atlantic, while the ENSO teleconnection pattern without NATL warming exhibits a Rossby wave-like pattern confined over the North Pacific and western Atlantic. Especially, the El Niño events with NATL warming show positive (negative) geopotential-height anomalies over the North Atlantic (Western Europe) which resemble the negative phase of the NAO. Consistently, it is shown using a simple statistical model that NATL SSTA in addition to the tropical Pacific SSTA leads to better prediction on regional climate variation over the North Atlantic and European regions. This role of NATL SST on ENSO teleconnection is also validated and discussed in a long term simulation of coupled global circulation model (CGCM).

the intensity of Nino 3.4 SST anomalies. The leading reproducible mode in JJA is clearer and more skilful for SLP than for Z500 and also seems related to the SST time evolution of tropical Pacific. It is characterised by an out-of-phase between the whole North Pacific and a horseshoe shaped area from Eastern Siberia and Gulf of Mexico. The leading OM mode found in MAM and SON, are quite close to the DJF one (at least for the modelled anomalies), but they are less skilful than in DJF. The most skilful mode (i.e. SLP-Z500 mode in DJF an SLP mode in JJA) is almost similar to the most reproducible one during these particular seasons. In MAM and SON, the SST-forced pattern is very close to the wintertime one. The warm episodes in the central and eastern tropical Pacific are then associated with negative pressure anomalies at the sea level and also at 500 hPa over the whole North Pacific and from SE US Coast to Western Europe (from SE US Coast to Scandinavia for Z500) and positive pressure anomalies on Central Canada, north of 55{sup 0}-60{sup 0} N across the North Atlantic and also over Northern Siberia (in MAM). The variance forced by SST are lower in MAM and SON than in DJF and, as suggested above, the skill of this SST-forced mode is weak in MAM and almost close to zero in SON.

The ECHAM 3.2 (T21), ECHAM (T30) and LMD (version 6, grid-point resolution with 96 longitudes x 72 latitudes) atmospheric general circulation models were integrated through the period 1961 to 1993 forces with the same observed Sea Surface Temperatures (SSTs) as compiled at the Hadley Centre. Three runs were made for each model starting from different initial conditions. The large-scale tropical inter-annual variability is analysed to give a picture of a skill of each model and of some sort of combination of the three models. To analyse the similarity of model response averaged over the same key regions, several widely-used indices are calculated: Southern Oscillation Index (SOI), large-scale wind shear indices of the boreal summer monsoon in Asia and West Africa and rainfall indices for NE Brazil, Sahel and India. Even for the indices where internal noise is large, some years are consistent amongst all the runs, suggesting inter-annual variability of the strength of SSTforcing. Averaging the ensemble mean of the three models (the super-ensemble mean) yields improved skill. When each run is weighted according to its skill, taking three runs from different models instead of three runs of the same model improves the mean skill. There is also some indication that one run of a given model could be better than another, suggesting that persistent anomalies could change its sensitivity to SST. The index approach lacks flexibility to assess whether a model's response to SST has been geographically displaced. It can focus on the first mode in the global tropics, found through singular value decomposition analysis, which is clearly related to El Nino/Southern Oscillation (ENSO) in all seasons. The Observed-Model and Model-Model analyses lead to almost the same patterns, suggesting that the dominant pattern of model response is also the most skilful mode. Seasonal modulation of both skill and spatial patterns (both model and observed) clearly exists with highest skill

Dynamic and numerical methods are used to discuss the atmospheric response to SST thermal forcing. The results show that for planetary scale systems, the standing SST thermal forcing can quickly excite a stable atmospheric equilibrium state response, which is characterized by obvious large-scale teleconnection oscillation in east-west and south-north directions. For synoptic scale systems, the SST thermal forcing mainly excites the atmospheric low-frequency oscillation. Some basic relation and dynamic processes between SST thermal forcing and atmospheric response pattern are revealed and some new viewpoints are presented.

The January-March (JFM) climate response of the Northern Hemisphere atmosphere to observed sea surface temperature (SST) anomalies for the period 1855-2002 is analysed from a 35-member ensemble made with SPEEDY, an atmospheric general circulation model (AGCM) of intermediate complexity. The model was run at the T30-L8 resolution, and initial conditions and the early stage of model runs differ among ensemble members in the definition of tropical diabatic heating. SST anomalies in the Nino3.4 region were categorised into five classes extending from strong cold to strong warm. Composites based on such a categorisation enabled an analysis of the influence of the tropical Pacific SST on the Northern Hemisphere atmospheric circulation with an emphasis on the Pacific-North America (PNA) and the North Atlantic-Europe (NAE) regions. As expected, the strongest signal was detected over the PNA region. An ''asymmetry'' in the model response was found for the opposite polarity of the Nino3.4 index; however, this asymmetry stems mainly from the difference in the amplitude of model response rather than from the phase shift between responses to warm and cold El Nino-Southern Oscillation (ENSO) events. The extratropical signal associated with warm ENSO events was found to be stronger than that related to cold events. The results also reveal that, for the PNA region, the amplitude of the response is positively correlated with the strength of ENSO, irrespective of the sign of ENSO. With almost no phase shift between model responses to El Nino and La Nina, the linear component of the response is much stronger than the non-linear component. Although the model climate response over the NAE region is much weaker than that over the PNA region, some striking similarities with the PNA are found. Both sea level pressure and precipitation responses are positively correlated with the strength of ENSO. This is not true for the 200-hPa geopotential heights, and no plausible

Rainfall over West Africa shows strong interannual variability related to changes in Sea Surface Temperature (SST). Nevertheless, this relationship seem to be non-stationary. A particular turning point is the decade of the 1970s, which witnessed a number of changes in the climatic system, including the climate shift of the late 1970s. The first aim of this study is to explore the change in the interannual variability of West African rainfall after this shift. The analysis indicates that the dipolar features of the rainfall variability over this region, related to changes in the Atlantic SST, disappear after this period. Also, the Pacific SST variability has a higher correlation with Guinean rainfall in the recent period. The results suggest that the current relationship between the Atlantic and Pacific El Nino phenomena is the principal responsible for these changes. A fundamental goal of climate research is the development of models simulating a realistic current climate. For this reason, the second aim of this work is to test the performance of Atmospheric General Circulation models in simulating rainfall variability over West Africa. The models have been run with observed SSTs for the common period 1957-1998 as part of an intercomparison exercise. The results show that the models are able to reproduce Guinean interannual variability, which is strongly related to SST variability in the Equatorial Atlantic. Nevertheless, problems in the simulation of the Sahelian interannual variability appear: not all models are able to reproduce the observed negative link between rainfall over the Sahel and El Nino-like anomalies in the Pacific, neither the positive correlation between Mediterranean SSTs and Sahelian rainfall. (orig.)

This study used National Center for Environmental Prediction (NCEP) reanalysis data to confirm that the variance of sea surface temperature (SST) in the South China Sea (SCS) has pronounced intraseasonal oscillations characterized by quasi-standing waves; and was aimed to document how intraseasonal time scale SST formed and developed in the SCS. The results derived from the composite analysis indicated the existence of a local low-level atmospheric dynamic forcing system over the SCS. The main formation mechanism of SST intraseasonal oscillation is the low-level rotational atmospheric circulation forcing over the SCS on intraseasonal time scales and the solar radiation variations caused by cloud amount changes.

The USCLI VAR working group on drought recently initiated a series of global climate model simulations forced with idealized SST anomaly patterns, designed to address a number of uncertainties regarding the impact of SSTforcing and the role of land-atmosphere feedbacks on regional drought. Specific questions that the runs are designed to address include: What are the mechanisms that maintain drought across the seasonal cycle and from one year to the next? What is the role of the leading patterns of SST variability, and what are the physical mechanisms linking the remote SSTforcing to regional drought, including the role of land-atmosphere coupling? The runs were carried out with five different atmospheric general circulation models (AGCM5), and one coupled atmosphere-ocean model in which the model was continuously nudged to the imposed SSTforcing. This paper provides an overview of the experiments and some initial results focusing on the responses to the leading patterns of annual mean SST variability consisting of a Pacific El Nino/Southern Oscillation (ENSO)-like pattern, a pattern that resembles the Atlantic Multi-decadal Oscillation (AMO), and a global trend pattern. One of the key findings is that all the AGCMs produce broadly similar (though different in detail) precipitation responses to the Pacific forcing pattern, with a cold Pacific leading to reduced precipitation and a warm Pacific leading to enhanced precipitation over most of the United States. While the response to the Atlantic pattern is less robust, there is general agreement among the models that the largest precipitation response over the U.S. tends to occur when the two oceans have anomalies of opposite sign. That is, a cold Pacific and warm Atlantic tend to produce the largest precipitation reductions, whereas a warm Pacific and cold Atlantic tend to produce the greatest precipitation enhancements. Further analysis of the response over the U.S. to the Pacific forcing highlights a number of

Full Text Available The ECHAM 3.2 (T21, ECHAM 4 (T30 and LMD (version 6, grid-point resolution with 96 longitudes × 72 latitudes atmospheric general circulation models were integrated through the period 1961 to 1993 forced with the same observed Sea Surface Temperatures (SSTs as compiled at the Hadley Centre. Three runs were made for each model starting from different initial conditions. The mid-latitude circulation pattern which maximises the covariance between the simulation and the observations, i.e. the most skilful mode, and the one which maximises the covariance amongst the runs, i.e. the most reproducible mode, is calculated as the leading mode of a Singular Value Decomposition (SVD analysis of observed and simulated Sea Level Pressure (SLP and geopotential height at 500 hPa (Z500 seasonal anomalies. A common response amongst the different models, having different resolution and parametrization should be considered as a more robust atmospheric response to SST than the same response obtained with only one model. A robust skilful mode is found mainly in December-February (DJF, and in June-August (JJA. In DJF, this mode is close to the SST-forced pattern found by Straus and Shukla (2000 over the North Pacific and North America with a wavy out-of-phase between the NE Pacific and the SE US on the one hand and the NE North America on the other. This pattern evolves in a NAO-like pattern over the North Atlantic and Europe (SLP and in a more N-S tripole on the Atlantic and European sector with an out-of-phase between the middle Europe on the one hand and the northern and southern parts on the other (Z500. There are almost no spatial shifts between either field around North America (just a slight eastward shift of the highest absolute heterogeneous correlations for SLP relative to the Z500 ones. The time evolution of the SST-forced mode is moderatly to strongly related to the ENSO/LNSO events but the spread amongst the ensemble of runs is not systematically related

Eight continental scale aerosol plumes exist each year as the enclosed image shows. Apparitions of seven plumes only exist for a few months in the same season each year whilst the East Asian Plume is visible all year. The aerosol optical depth (AOD) of all the plumes varies enormously interannually with two studies showing the surface radiative forcing of the South East Asian Plume (SEAP) as -150W/m2 and -286W/m2/AOD. I show that the SEAP, created by volcanic aerosols (natural) and biomass burning and gas flares in the oil industry (anthropogenic), is the sole cause of all El Nino events, the greatest interannual perturbation of the atmospheric circulation system. The SEAP creates an El Nino by absorbing solar radiation at the top of the plume which heats the upper atmosphere and cools the surface. This creates a temperature inversion compared to periods without the plume and reduces convection. With reduced convection in SE Asia, the Maritime Continent, the Trade Winds blowing across the Pacific are forced to relax as their exit into the Hadley and Walker Cells is constrained and the reduced Trade Wind speed causes the Sea Surface Temperature (SST) to rise in the central tropical Pacific Ocean as there is a strong negative correlation between wind speed and SST. The warmer SST in the central Pacific creates convection in the region which further reduces the Trade Wind speed and causes the Walker Cell to reverse - a classic El Nino. Having established the ability of such extreme aerosol plumes to create El Nino events I will then show how the South American, West African, Middle East and SEAP plumes create drought in the Amazon, Spain, Darfur and Australia as well as causing the extremely warm autumn and winter in Europe in 2006-07. All these effects are created by the plumes reducing convection in the region of the plume which forces the regional Hadley Cells into anomalous positions thereby creating persistent high pressure cells in the mid latitudes. This

SST-forced tropical-channel simulations are used to quantify the control of shortwave (SW) parameterization on the mean tropical climate compared to other major model settings (convection, boundary layer turbulence, vertical and horizontal resolutions), and to pinpoint the physical mechanisms whereby this control manifests. Analyses focus on the spatial distribution and magnitude of the net SW radiation budget at the surface (SWnet_SFC), latent heat fluxes, and rainfall at the annual timescale. The model skill and sensitivity to the tested settings are quantified relative to observations and using an ensemble approach. Persistent biases include overestimated SWnet_SFC and too intense hydrological cycle. However, model skill is mainly controlled by SW parameterization, especially the magnitude of SWnet_SFC and rainfall and both the spatial distribution and magnitude of latent heat fluxes over ocean. On the other hand, the spatial distribution of continental rainfall (SWnet_SFC) is mainly influenced by convection parameterization and horizontal resolution (boundary layer parameterization and orography). Physical understanding of the control of SW parameterization is addressed by analyzing the thermal structure of the atmosphere and conducting sensitivity experiments to O3 absorption and SW scattering coefficient. SW parameterization shapes the stability of the atmosphere in two different ways according to whether surface is coupled to atmosphere or not, while O3 absorption has minor effects in our simulations. Over SST-prescribed regions, increasing the amount of SW absorption warms the atmosphere only because surface temperatures are fixed, resulting in increased atmospheric stability. Over land-atmosphere coupled regions, increasing SW absorption warms both atmospheric and surface temperatures, leading to a shift towards a warmer state and a more intense hydrological cycle. This turns in reversal model behavior between land and sea points, with the SW scheme that

East Asia has a significant concentration of pollutant aerosols, mostly due to rapid industrialization. Previous research indicates that the aerosol effect from Asian pollution outflow could account for the trend of increasing deep convective clouds, as well as an intensification of the storm track, over the North Pacific Ocean in winter since the mid-1990s. However, it is not clear whether such change is solely due to Asian pollutant forcings or not. To understand the relative roles of Asian pollutant aerosols and sea surface temperature (SST) forcings on the precipitation change in the North Pacific, we examine the interannual variation of particulate matter 2.5 (PM2.5) simulated in the global chemical transport model (GEOS-Chem) and the idealized experiments using the Community Atmosphere Model version 5 (CAM5) for 1986-2010. The composite analysis indicates that the changes in precipitation amount and storm track intensity in the southwestern North Pacific might be associated with the increase in PM2.5 concentration in East China. However, El Niño-like warming during the years of high PM2.5 concentration may also influence the precipitation amount, as well as the storm track intensity in the central and eastern North Pacific. Model experiments also indicate that the El Niño-like warming and the Asian pollutant aerosols have different effects on precipitation amounts in the North Pacific. Therefore, the precipitation changes, as well as the intensification of the storm track, in the North Pacific might be attributed to both Asian pollutant aerosols and SSTforcing in the tropics.

Full Text Available Climate change can sometimes be reflected in variations in lake levels, thus understanding variations in lake levels and their relationship to climate change plays an important role in studying climate change. In this study, about 10 years of Topex/Poseidon (T/P altimetric data and 6 years of Jason-1 data were used to compute time series of level variations of six lakes in the Central and East Asia. The study sites were Hongze, La-ang, Ulungur, Khanka, Issyk-kul and Baikal Lakes. Time series of level variations were analyzed by means of the wavelet spectrum for inter-annual (between 2 to 4 years, annual and semiannual signals. Since 2000, water level variations of Issyk-kul, Ulungur and Khanka lakes were larger than those of Baikal and Hongze. Correlations between the NINO3.4 sea surface temperature (SST and the level variations of the six lakes were analyzed. For Baikal and Khanka Lakes, the correlations were significant (+0.3834 and +0.3334 for 3 - 5 months after the occurrence of ENSO, while the correlation for La-ang Lake was the weakest (< 0.1, indicating that ENSO showed a lag influence on variation in lake levels in the Central and East Asia.

Spatial and temporal variability of sea surface temperature (SST) is closely related to the substantial heat content of the ocean mixed layer, which...salinity from Polar Science Center (PSC) Hydrographic Clima - tology (PHC) (Steele et al., 2001). This relaxation is designed to keep the evaporation...advection, which were generally small in the 0.72° model. The accuracy of SST from each simulation was evaluated in comparison to a satellite-based clima

"Warm pool" (WP) El Nino events are characterized by positive sea surface temperature (SST) anomalies in the central equatorial Pacific. During austral spring, WP El Nino events are associated with an enhancement of convective activity in the South Pacific Convergence Zone, provoking a tropospheric planetary wave response and thus increasing planetary wave driving of the Southern Hemisphere stratosphere. These conditions lead to higher polar stratospheric temperatures and to a weaker polar jet during austral summer, as compared with neutral ENSO years. Furthermore, this response is sensitive to the phase of the quasi-biennial oscillation (QBO): a stronger warming is seen in WP El Nino events coincident with the easterly phase of the quasi-biennial oscillation (QBO) as compared with WP El Nino events coincident with a westerly or neutral QBO. The Goddard Earth Observing System (GEOS) chemistry-climate model (CCM) is used to further explore the atmospheric response to ENSO. Time-slice simulations are forced by composited SSTs from observed NP El Nino and neutral ENSO events. The modeled eddy heat flux, temperature and wind responses to WP El Nino events are compared with observations. A new gravity wave drag scheme has been implemented in the GEOS CCM, enabling the model to produce e realistic, internally generated QBO. By repeating the above time-slice simulations with this new model version, the sensitivity of the WP El Nino response to the phase of the quasi-biennial oscillation QBO is estimated.

It is increasingly accepted that any possible climate change will not only have an influence on mean climate but may also significantly alter climatic variability. A change in the distribution and magnitude of extreme rainfall events (associated with changing variability), such as droughts or flooding, may have a far greater impact on human and natural systems than a changing mean. This issue is of particular importance for environmentally vulnerable regions such as southern Africa. The subcontinent is considered especially vulnerable to and ill-equipped (in terms of adaptation) for extreme events, due to a number of factors including extensive poverty, famine, disease and political instability. Rainfall variability is a function of scale, so high spatial and temporal resolution data are preferred to identify extreme events and accurately predict future variability. In this research, high resolution satellite derived rainfall data from the Microwave Infra-Red Algorithm (MIRA) are used as a basis for undertaking model experiments using a state-of-the-art regional climate model. The MIRA dataset covers the period from 1993-2002 and the whole of southern Africa at a spatial resolution of 0.1 degree longitude/latitude. Once the model's ability to reproduce extremes has been assessed, idealised regions of sea surface temperature (SST) anomalies are used to force the model, with the overall aim of investigating the ways in which SST anomalies influence rainfall extremes over southern Africa. In this paper, results from sensitivity testing of the regional climate model's domain size are briefly presented, before a comparison of simulated daily rainfall from the model with the satellite-derived dataset. Secondly, simulations of current climate and rainfall extremes from the model are compared to the MIRA dataset at daily timescales. Finally, the results from the idealised SST experiments are presented, suggesting highly nonlinear associations between rainfall extremes

Information is presented regarding "El Nino," a warm ocean current which has a profound worldwide effect on ocean life and weather patterns. Suggestions are provided for teaching students about the current and other related topics. (CB)

The Yangtze River valley (YRV), located in central-eastern China, has witnessed increased numbers of heat waves in the summer since 1951. Knowing what factors control and affect the interannual variability of heat waves, especially distinguishing the contributions of anomalous sea surface temperature (SST) forcings and those of internal modes of variability, is important to improving heat wave prediction. After evaluating 70 members of the atmospheric model intercomparison project (AMIP) experiments from the 25 models that participated in the coupled model intercomparison project phase 5 (CMIP5), 13 high-skill members (HSMs) are selected to estimate the SST-forced variability. The results show that approximately 2/3 of the total variability of the July-August heat waves in the YRV during 1979-2008 can be attributed to anomalous SSTforcings, whereas the other 1/3 are due to internal variability. Within the SST-forced component, one-half of the influence is from the impact of the El Niño-Southern Oscillation (ENSO) and the other half is from non-ENSO related SSTforcings, specifically, the SST anomalies in the North Pacific and the North Atlantic. Both the decaying El Niño and developing La Niña accompanied by a warm Indian Ocean and cold central Pacific, respectively, are favorable to hotter summers in the YRV because these patterns strengthen and extend the western North Pacific Subtropical High (WNPSH) westwards, for which the decaying ENSO plays a dominant role. The internal variability shows a circumglobal teleconnection in which Rossby waves propagate southeastwards over the Eurasian Continent and strengthen the WNPSH. Atmospheric model sensitivity experiments confirm that non-ENSO SSTforcings can modulate the WNPSH and heat wave variability by projecting their influences onto the internal mode.

Ethiopian economy and society are strongly dependent on agriculture and therefore rainfall. Reliable forecasts for the rainy seasons are important to allow for agricultural planning and drought preparations. The operational seasonal forecasts for Ethiopia are based on analogue methods relying mainly on sea surface temperature (SST) indices. A better understanding of the physical links between Ethiopian rainfall and SST may help to improve forecasts. The highest rainfall rates are observed in the Kiremt season (defined as JJAS), which is the rainy season in Central and Northwestern Ethiopia. Kiremt rainfall shows clear negative correlation with Central Pacific SST, linking dry Ethiopian summers with ENSO-like warm SST anomalies. We use the atmosphere general circulation model Echam5.3 to investigate the physical link between Pacific SST anomalies and Kiremt rainfall. We compare a historical simulation with a T106 horizontal resolution (~ 1.125°), forced with reconstructed SST data, to gauge-based rainfall observations for the time period of 1961 to 2009. Composite analysis for model and observations show warm SST anomalies in the Central Pacific and a corresponding large-scale circulation anomaly with subsidence over Ethiopia in dry Kiremt seasons. Horizontal wind fields show a slow-down of the whole Indian monsoon system with a weaker Tropical Easterly Jet (TEJ) and a weaker East African Low-Level Jet (EALLJ) in these summers. We conducted a sensitivity experiment with El Nino like SST anomalies in the Central Pacific with the same Echam version. Its results show that warm Pacific SST anomalies cause dry summer conditions over Ethiopia. While the large-scale subsidence over East Africa is present in the experiment, there is no significant weakening of the Indian monsoon system. We rather find an anomalous circulation cell over Northern Africa with westerlies at 100-200 hPa and easterlies below 500 hPa. The anomalous easterly flow in the lower and middle

The El Nino event of 1997-1998 followed by the La Nina in 1998-1999 was the strongest of its kind encountered in the 20t h century. Associated with this event Indonesia experienced severe drought leading to large forest fires. Large aerosol plume from these fires has advected over the Equatorial Indian Ocean region. Development and decay of this plume and its regional transport are studied using aerosol optical depth (AOD) derived from NOAA-14 AVHRR data using the Discrete Ordinate Method along with the tropospheric circulation derived from NCEP/NCAR reanalysis. In the second half of 1997 extensive smoke and haze episodes are observed over the tropical Indian Ocean in the latitude range of 5° N to 10° S. The AOD values at 630nm often exceeded 1.0 near Indonesia and in the southeastern parts of Bay of Bengal. Development of this plume started from September and continued up to the first half of November. During first half of September, the plume was conf ined to the coastal regions of Indonesia and then started developing towards west to reach up to 60°E. Decay of the plume started by the middle of November and subsided almost completely by December. During the development phase this plume showed a consistent increase in AOD from western Indian Ocean to Eastern part of tropical Indian Ocean. This westward transport of aerosols from the Indonesian region was confined to the equatorial latitudes. This was due to the reversal of zonal circulation during the El Nino period leading to large westward wind anomaly in the equatorial Indian Ocean region. Westward propagation of the aerosol plume is arrested near ~60°E because of the large convection and rainfall caused by El Nino in this longitude region. The El Nino related weather and atmospheric dynamics is found to have significantly influenced the regional aerosol distribution over the Indian Ocean. On an average, the diurnal mean clear sky aerosol radiative forcing at top of atmosphere (TOA) is estimated to be

Associated with the double Inter-tropical convergence zone problem, a dipole SST bias pattern (cold in the equatorial central Pacific and warm in the southeast tropical Pacific) remains a common problem inherent in many contemporary coupled models. Based on a newly-developed coupled model, we performed a control run and two sensitivity runs, one is a coupled run with annual mean SST correction and the other is an ocean forced run. By comparison of these three runs, we demonstrated that a serious consequence of this SST bias is to severely suppress the thermocline feedback in a realistic simulation of the El Nino/Southern Oscillation. Firstly, the excessive cold tongue extension pushes the anomalous convection far westward from the equatorial central Pacific, prominently diminishing the convection-low level wind feedback and thus the air-sea coupling strength. Secondly, the equatorial surface wind anomaly exhibits a relatively uniform meridional structure with weak gradient, contributing to a weakened wind-thermocline feedback. Thirdly, the equatorial cold SST bias induces a weakened upper-ocean stratification and thus yields the underestimation of the thermocline-subsurface temperature feedback. Finally, the dipole SST bias underestimates the mean upwelling through (a) undermining equatorial mean easterly wind stress, and (b) enhancing convective mixing and thus reducing the upper ocean stratification, which weakens vertical shear of meridional currents and near-surface Ekman-divergence. (orig.)

By using monthly historical sea surface temperature (SST) data for the years from 1950 to 2000, the Western Pacific Warm Pool (WPWP) climatology and anomalies are studied in this paper. The analysis of WPWP centroid (WPWPC)movement anomalies and the Nino-3 region SST anomalies(SSTA) seems to reveal a close, linear relation between the zonal WPWPC and Nino-3 region SSTA, which suggests that a 9° anomaly of the zonal displacement from the climatological position of the WPWPC corresponds to about a 1℃ anomaly in the Nino-3 region area-mean SST. This study connects the WPWPC zonal displacement with the Nino-3 SSTA, and it may be helpful in better understanding the fact that the WPWP eastward extension is conducive to the Nino-3 region SST increase during an El Nino-Southern Oscillation (ENSO) event.

Both seasonal potential predictability and the impact of SST in the Pacific on the forecast skill over China are investigated by using a 9-level global atmospheric general circulation model developed at the Institute of Atmospheric Physics under the Chinese Academy of Sciences (IAP9L-AGCM). For each year during 1970 to 1999, the ensemble consists of seven integrations started from consecutive observational daily atmospheric fields and forced by observational monthly SST. For boreal winter, spring and summer,the variance ratios of the SST-forced variability to the total variability and the differences in the spatial correlation coefficients of seasonal mean fields in special years versus normal years are computed respectively. It follows that there are slightly inter-seasonal differences in the model potential predictability in the Tropics. At northern middle and high latitudes, prediction skill is generally low in spring and relatively high either in summer for surface air temperature and middle and upper tropospheric geopotential height or in winter for wind and precipitation. In general, prediction skill rises notably in western China, especially in northwestern China, when SST anomalies (SSTA) in the Nino-3 region are significant. Moreover,particular attention should be paid to the SSTA in the North Pacific (NP) if one aims to predict summer climate over the eastern part of China, i.e., northeastern China, North China and southeastern China.

Recent studies report that two types of El Nino events have been observed. One is the cold tongue El Nino or Eastern Pacific El Nino (EP El Nino), which is characterized by relatively large sea surface temperature (SST) anomalies in the eastern Pacific, and the other is the warm pool El Nino (a.k.a. 'Central Pacific El Nino' (CP El Nino) or 'El Nino Modoki'), in which SST anomalies are confined to the central Pacific. Here the vertical structure variability of the periods during EP and CP is investigated based on the GFDL{sub C}M2.1 model in order to explain the difference in equatorial wave dynamics and associated negative feedback mechanisms. It is shown that the mean stratification in the vicinity of the thermocline of the central Pacific is reduced during CP El Nino, which favours the contribution of the gravest baroclinic mode relatively to the higher-order slower baroclinic mode. Energetic Kelvin and first-meridional Rossby wave are evidenced during the CP El Nino with distinctive amplitude and propagating characteristics according to their vertical structure (mostly first and second baroclinic modes). In particular, the first baroclinic mode during CP El Nino is associated to the ocean basin mode and participates to the recharge process during the whole El Nino cycle, whereas the second baroclinic mode is mostly driving the discharge process through the delayed oscillator mechanism. This may explain that the phase transition from warm to neutral/cold conditions during the CP El Nino is delayed and/or disrupted compared to the EP El Nino. Our results have implications for the interpretation of the variability during periods of high CP El Nino occurrence like the last decade. (orig.)

In this study, we investigated the oceanic and atmospheric response to the March 1997 WWE (Westerly Wind Event) that is suggested to have played an important role in the onset of the 1997-1998 El Nino. We first explored the impact of this event on the evolution of the tropical Pacific Ocean using an ocean General Circulation Model (GCM). The ocean response was characterised by (i) a cooling of the far western Pacific (~0.8 C), (ii) a rapid eastward displacement of the warm-pool (2000 km in a month), and (iii) a weak warming of the central eastern Pacific along the path of the oceanic Kelvin wave, excited by the WWE (~0.5 C). We have then investigated the atmospheric response to these modifications of the sea surface temperature (SST) by using an atmospheric GCM forced with the SST anomalies from the ocean-only experiments. The results have demonstrated that the three aspects of the SST anomaly field, generated by the WWE, themselves initiate two types of atmospheric response, both of which favoured a rapid growth toward El Nino conditions. First, the eastward displacement of the warm-pool, together with the reduction of the east-west SST gradient along the forced oceanic Kelvin wave path, resulted in a weakening of the trade winds in the central-eastern Pacific. Second, the eastward displacement of the warmest water from the western to the central Pacific, giving rise to a cooling in the far western Pacific, induces an eastward shift of convection that consequently promotes the occurrence of further frequent and intense WWEs in the following months. The characteristics of these later WWEs are controlled both by the eastward extension of the warm-pool and by the SST gradients established in the far western Pacific. The implications of these results for the onset of the 1997-98 El Nino have been considered, with the conclusion that the intense March WWE strongly contributed to the early onset and rapid growth rate of the 1997-1998 El Nino, not only by its direct

Observations indicate that the Atlantic zonal mode influences El Nino Southern oscillation (ENSO) in the Pacific, as already suggested in previous studies. Here we demonstrate for the first time using partial coupled experiments that the Atlantic zonal mode indeed influences ENSO. The partial coupling experiments are performed by forcing the coupled general circulation model (ECHAM5/MPI-OM) with observed sea surface temperature (SST) in the Tropical Atlantic, but with full air-sea coupling allowed in the Pacific and Indian Ocean. The ensemble mean of a five member simulation reproduces the observational results well. Analysis of observations, reanalysis, and coupled model simulations all indicate the following mechanism: SST anomalies associated with the Atlantic zonal mode affect the Walker Circulation, driving westward wind anomalies over the equatorial Pacific during boreal summer. The wind stress anomalies increase the east-west thermocline slope and enhance the SST gradient across the Pacific; the Bjerknes positive feedback acts to amplify these anomalies favouring the development of a La Nina-like anomalies. The same mechanisms act for the cold phase of Atlantic zonal mode, but with opposite sign. In contrast to previous studies, the model shows that the influence on ENSO exists before 1970. Furthermore, no significant influence of the Tropical Atlantic on the Indian Monsoon precipitation is found in observation or model. (orig.)

El Nino/Southern Oscillation (ENSO) will still be the most dominant year-to-year variations of the future tropical climate system. A global high-resolution atmospheric general circulation model with grid size about 20 km is used to project future changes in rainfall extremes associated with El Nino at the end of the 21st century. Four different spatial patterns in sea surface temperature (SST) changes are used as future boundary conditions based on the CMIP5 RCP8.5 scenario. Rainfall extremes such as the maximum 5-day precipitation total (Rx5d) over the western Pacific are positively correlated to the Nino3.4 SST anomalies. It is found that Rx5d regressed to the Nino3.4 SST will increase two times in the future compared to the present value. This implies drastic increase of risk of heavy-rainfall induced disasters under by global warming over the western Pacific countries.

In 1997, a child's tantrums caught the world's attention. These tantrums took the form not of crying and foot stamping, but of droughts and floods. Obviously, this was no ordinary child. It was, in fact, The Child, or El Nino, as it was, named in the late 1800s by South American observers, who noted that its timing coincided with the Christmas holiday. El Nino is a reversal in sea surface temperature (SST) distributions that occurs once every few years in the tropical Pacific. When it coincides with a cyclical shift in air pressure, known as the Southern Oscillation, normal weather patterns are drastically altered. The combined phenomenon is known as El Nino-Southern Oscillation (ENSO). Although ENSO is a regular phenomenon, it was unusually strong in 1997. It produced heavy rainfall and floods in California and bestowed spring-like temperatures on the Midwest during the winter. These drastic changes in normal weather patterns captured the public imagination, from news reports to jokes on late-night talk shows. Naturally, people wanted to. know as much, about El Nino as possible. Fortunately, scientists had at their disposal new satellites and ocean sensors that provided an unprecedented level of information. Consequently, not only was the 1997 ENSO the strongest in recent memory, but it was also the most thoroughly studied. Prominent groups such as the NASA Seasonalto-Interannual Prediction Project (NSIPP) combined numerous aspects of climate modeling into a single, predictive endeavor.

In this paper, climatic features of sea temperature of western Pacific warm pool and the relationship with sea surface temperature (SST) of its adjacent regions are analyzed based on the observed sea temperature on vertical cross section along 137°E in western Pacific, the monthly mean SST of Xisha Station in South China Sea and the global monthly mean SST with resolution of 1°× 1° (U. K./GISST2.2). The results indicate that (1) in a sense of correlation, SST of western Pacific warm pool can represent its sea subsurface temperature from surface to 200 m-depth level in winter, and it can only represent sea temperature from surface to 70 m depth in summer. The sea subsurface temperature anomaly of warm pool may be more suitable for representing thermal regime of western Pacific warm pool. The sea subsurface temperature of warm pool has a characteristic of quasi-biennial oscillation. (2) Warm pool and Kuroshio current are subject to different ocean current systems. (3) Furthermore, the relationship between SST of Xisha Station and SST of warm pool has a characteristic of negative correlation in winter and positive correlation in summer, and a better lag negative correlation of SST of Xisha Station with sea subsurface temperature of warm pool exists. (4) Additionally, oscillation structure of sea temperature like "a seesaw" exists in between warm pool and Regions Nino3 and Nino4. January (June) maximum(minimum) sea subsurface temperature anomaly of warm pool may serve as a strong signal that indicates maturity phase (development phase) of La Nina (El Nino) event, it also acts as a strong signal which reveals variations of SST of Regions Nino3 and Nino4.

The Atlantic Multidecadal Oscillation (AMO) is a mode of North Atlantic sea surface temperature (SST) variability that has substantial impacts on Northern Hemisphere precipitation and temperature patterns, as well as Atlantic hurricane activity. Climate models and paleoclimate data suggest that the warm AMO phase can enhance drought in the American mid- and southwest, increase rainfall intensity and amounts in North Eastern Brazil and the African Sahel region, and increase the number of severe Atlantic hurricanes. While models and instrumental data provide some support for the AMO as an internal climate ';oscillation', questions remain regarding the proportion of AMO variability resulting from internal and external forcing, and more specifically, how much of the recent (i.e. late 20th century) north Atlantic warming is anthropogenically forced. Several studies have addressed these issues and proposed various methods for diagnosing the AMO using historical climate model simulations (e.g. from CMIP3) and instrumental data. Here we present results from analyses of the North Atlantic region in historical simulations from Climate Model Intercomparison Project 5 (CMIP5). Our approach involves (1) analyzing a grand ensemble mean based on averaging realizations of all available models, such that random, internal variability components cancel and only a forced component remains; (2) for all models with at least four realizations, estimating a forced component by averaging multiple realizations and estimating internal variability components from the residual series of individual realizations and (3) analyzing control simulations for the corresponding models to assess whether or not there is evidence of enhanced AMO-like internal variability.

This study is the first to identify a robust El Nino/Southern Oscillation (ENSO) signal in the Antarctic stratosphere. El Nino events are classified as either conventional "cold tongue" events (positive SST anomalies in the Nino 3 region) or "warm pool" events (positive SST anomalies in the Nino 4 region). The ERA-40, NCEP and MERRA meteorological reanalyses are used to show that the Southern Hemisphere stratosphere responds differently to these two types of El Nino events. Consistent with previous studies, "cold tongue" events do not impact temperatures in the Antarctic stratosphere. During "warm pool" El Nino events, the poleward extension and increased strength of the South Pacific Convergence Zone (SPCZ) favor an enhancement of planetary wave activity during the SON season. On average, these conditions lead to higher polar stratospheric temperatures and a weakening of the Antarctic polar jet in November and December, as compared with neutral ENSO years. The phase of the quasi-biennial oscillation (QBO) modulates the stratospheric response to "warm pool" El Nino events: the strongest planetary wave driving events are coincident with the easterly phase of the QBO.

El Nino Southern Oscillation (ENSO) is an important driver of interannual variations in climate and ecosystem productivity in tropical regions. However, detailed information about this important phenomenon of the Indian Ocean is scarce. Consequently, the objective of this study is to improve understanding of the impact of warm event El Nino and cool event La Nina on annual tuna landings from the Indian Ocean from 1980 to 2010. In this study, maximum tuna landings were recorded during a weak El Nino year (1456054 t in 2006) and during a weak La Nina year (1243562 t in 2000), although the lowest tuna catch was followed during the strong El Nino year (1204119 t in 2009) and during a strong La Nina year (706546 t in 1988). Validation of predicted tuna landings and SST were showing a significant positive correlation (p Nino years; landings in Indian Ocean tend to be optimum SST 25 to 26°C in ENSO event. Our results confirm the ENSO impact on climate, tuna abundance and production in the Indian Ocean. However, among the oceanic variables SST explained the highest deviance in generalized additive models and therefore considered the best habitat predictor in the Indian Ocean followed by sea level pressure and Winds (U, V, W).

An increase of mass and heat content in the equatorial band of the Pacific Ocean, and in particular in the western part of the basin, appears necessary for the initiation of El Nino. This build up has led to the recharge theory of El Nino. The western Pacific warm pool is also characterized by the presence of specific salinity stratification known as the barrier layer. This barrier isolates the warm surface water from entrainment cooling and potentially preserves the heat content prior to El Nino. The importance of salinity stratification in the build up of El Nino is investigated using a general circulation coupled model of the tropical Pacific. The Meteo-France/ARPEGE global atmospheric model coupled to the LODYC/OPA ocean model is able to reproduce self-sustained El Nino events. In particular, this coupled model displays an increase of heat content in the western equatorial Pacific the year prior to each El Nino event. The methodology consists of removing the stratification effect of salinity in the vertical mixing parameterization the year prior to El Nino, and then plugs it back. The cutoff is restricted to the western side of the equatorial band where sea surface temperature (SST) is greater than 28C. By removing the barrier layer the year prior to El Nino, the main effect is to reduce the ocean heat content in the western part of the equatorial band and increase it in the east. When the stratification effect of salinity is plug back, El Nino is greatly reduced or even aborted. This has tested over three El Nino events of different intensities and through 5 additional member ensemble. The failure for El Nino to start is statistically significant and proves that salinity stratification plays a crucial role in the build up of El Nino. Detailed analyses indicate that vertical diffusion in the warm pool and SST-wind coupling in the central Pacific are essential to set up the favorable condition for the initiation of El Nino.

On the basis of NOAA/CPC data of sea surface temperature anomaly in the Nino regions during Jan. 1950 - Dec. 2003, the wavelet power spectrum of SST were studied with significance and confidence testing at different scales in this paper. It shows that the SST are provided with multi-time scales structure nested one another, and vary on scales of 2 - 7 years, 8 - 20 years and ＞30 years. The most significant variation of the warm and cold episodes is in the 4-year band of period. The power, frequency structure and confidence of the same episode are different in different Nino regions. The intensity of oscillations is increasing at low frequency bands and decreasing at high frequency bands from east to west in the Nino regions, especially after 1970.

Warm pool El Nino (WPEN) events are characterized by positive sea surface temperature (SST) anomalies in the central equatorial Pacific in austral spring and summer. Previous work found an enhancement in planetary wave activity in the South Pacific in austral spring, and a warming of 3-5 K in the Antarctic lower stratosphere during austral summer, in WPEN events as compared with ENSO neutral. In this presentation, we show that weakening of the Antarctic vortex during WPEN affects the structure and magnitude of high-latitude total ozone. We use total ozone data from TOMS and OMI, as well as station data from Argentina and Antarctica, to identify shifts in the longitudinal location of the springtime ozone minimum from its climatological position. In addition, we examine the sensitivity of the WPEN-related ozone response to the phase of the quasi-biennial oscillation (QBO). We then compare the observed response to WPEN events with Goddard Earth Observing System chemistry-climate model, version 2 (GEOS V2 CCM) simulations. Two, 50-year time-slice simulations are forced by annually repeating SST and sea ice climatologies, one set representing observed WPEN events and the second set representing neutral ENSO events, in a present-day climate. By comparing the two simulations, we isolate the impact of WPEN events on lower stratospheric ozone, and furthermore, examine the sensitivity of the WPEN ozone response to the phase of the QBO.

The US CLIVAR working group on drought recently initiated a series of global climate model simulations forced with idealized SST anomaly patterns, designed to address a number of uncertainties regarding the impact of SSTforcing and the role of land-atmosphere feedbacks on regional drought. Specific questions that the runs are designed to address include: What are mechanisms that maintain drought across the seasonal cycle and from one year to the next. What is the role of the land? What is the role of the different ocean basins, including the impact of EL Nino/Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), the Atlantic Multi-decadal Oscillation (AMO), and warming trends in the global oceans? The runs were done with several global atmospheric models including NASA/NSIPP-1, NCEP/GFS, GFDL/AM2, and NCAR CCM3 and CAM3. In addition, runs were done with the NCEP CFS (coupled atmosphere-ocean) model by employing a novel adjustment technique to nudge the coupled model towards the imposed SSTforcing patterns. This talk provides an overview of the experiments and some initial results.

The seasonal change in the relationship between El Nino and Indian Ocean dipole (IOD) is examined using the European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40), and the twentieth century simulations (20c3m) from the Geophysical Fluid Dynamics Laboratory Coupled Model, version 2.1. It is found that, both in ERA-40 and the model simulations, the correlation between El Nino (Nino3 index) and the eastern part of the IOD (90-110 E; 10 S-equator) is predominantly positive from January to June, and then changes to negative from July to December. Correlation maps of atmospheric and oceanic variables with respect to the Nino3 index are constructed for each season in order to examine the spatial structure of their seasonal response to El Nino. The occurrence of El Nino conditions during January to March induces low-level anti-cyclonic circulation anomalies over the southeastern Indian Ocean, which counteracts the climatological cyclonic circulation in that region. As a result, evaporation decreases and the southeastern Indian Ocean warms up as the El Nino proceeds, and weaken the development of a positive phase of an IOD. This warming of the southeastern Indian Ocean associated with the El Nino does not exist past June because the climatological winds there develop into the monsoon-type flow, enhancing the anomalous circulation over the region. Furthermore, the development of El Nino from July to September induces upwelling in the southeastern Indian Ocean, thereby contributing to further cooling of the region during the summer season. This results in the enhancement of a positive phase of an IOD. Once the climatological circulation shifts from the boreal summer to winter mode, the negative correlation between El Nino and SST of the southeastern Indian Ocean changes back to a positive one. (orig.)

Considering the multiscale character of LFO (low-frequency oscillation) in the tropical atmosphere, the effects of SST on LFO in the tropical atmosphere are discussed by using an absolute ageostrophic, baroclinic model. Here, SST effects include sea surface heating and forcing of SST anomalies (SSTAs). Studies of the influences of sea surface heating on LFO frequency and stability show that sea surface heating can slow the speed of waves and lower their frequency when SST is comparatively low; while higher SST leads to unstable waves and less periods of LFO. Since the impact of a SSTA on ultra-long waves is more evident than that on kilometer-scale waves, long-wave approximation is used when we continue to study the effect of SSTAs. Results indicate that SSTAs can lead to a longer period of LFO, and make waves unstable. In other words,positive (negative) SSTAs can make waves decay (grow).

The Madden-Julian Oscillation (MJO) is the dominant mode of tropical variability at intraseasonal timescales. It displays substantial interannual variability in intensity which may have important implications for the predictability of the coupled system. The reasons for this interannual variability are not understood. The aim of this paper is to investigate whether the interannual behavior of the MJO is related to tropical sea surface temperature (SST) anomalies, particularly El Nino, and hence whether it is predictable. The interannual behavior of the MJO has been diagnosed initially in the 40-year NCEP/ NCAR Reanalysis. The results suggest that prior to the mid-1970s the activity of the MJO was consistently lower than during the latter part of the record. This may be related to either inadequacies in the data coverage, particularly over the tropical Indian Ocean prior to the introduction of satellite observations, or to the real effects of a decadal timescale warming in the tropical SSTs. The teleconnection patterns between interannual variations in MJO activity and SST show only a weak, barely significant, influence of El Nino in which the MJO is more active during the cold phase. As well as the NCEP/NCAR Reanalysis, a 4-member ensemble of 45 year integrations with the Hadley Centre climate model (HadAM2a), forced by observed SSTs for 1949-93, has been used to investigate the relationship between MJO activity and SST. HadAM2a is known to give a reasonable simulation of the MJO and the extended record provided by this ensemble of integrations allows a more robust investigation of the predictability of MJO activity than was possible with the 40-year NCEP/NCAR Reanalysis. The results have shown that, for the uncoupled system, with the atmosphere being driven by imposed SSTS, there is no reproducibility for the activity of the MJO from year to year. The interannual behavior of the MJO is not controlled by the phase of El Nino and would appear to be chaotic in

. Methods include historical studies to understand past patterns and to test hindcasts of the prediction tools, crop modeling, spatial analysis and remote sensing. This research involves expanding, deepening, and applying the understanding of physical climate to the fields of agronomy and social science; and the reciprocal understanding of crop growth and farm economics to climatology. Delivery of a regional climate forecast with no information about how the climate forecast was derived limits its effectiveness. Explanation of a region's major climate driving forces helps to place a seasonal forecast in context. Then, a useful approach is to show historical responses to previous El Nino events, and projections, with uncertainty intervals, of crop response from dynamic process crop growth models. Regional ID forecasts should be updated with real-time weather conditions. Since every El Nino event is different, it is important to track, report and advise on each new event as it unfolds. The stability of human enterprises depends on understanding both the potentialities and the limits of predictability. Farmers rely on past experience to anticipate and respond to fluctuations in the biophysical systems on which their livelihoods depend. Now scientists are improving their ability to predict some major elements of climate variability. The improvements in the reliability of El Nino forecasts are encouraging, but seasonal forecasts for agriculture are not, and will probably never be completely infallible, due to the chaotic nature of the climate system. Uncertainties proliferate as we extend beyond Pacific sea-surface temperatures to climate teleconnections and agricultural outcomes. The goal of this research is to shed as a clear light as possible on these inherent uncertainties and thus to contribute to the development of appropriate responses to El Nino and other seasonal forecasts for a range of stakeholders, which, ultimately, includes food consumers everywhere.

The USCLIVAR working group on drought recently initiated a series of global climate model simulations forced with idealized SST anomaly patterns, designed to address a number of uncertainties regarding the impact of SSTforcing and the role of land-atmosphere feedbacks on regional drought. Specific questions that the runs are designed to address include, What are the mechanisms that maintain drought across the seasonal cycle and from one year to the next? What is the role of the leading patterns of SST variability, and what are the physical mechanisms linking the remote SSTforcing to regional drought, including the role of land-atmosphere coupling? The runs were carried out with five different atmospheric general circulation models (AGCMs), and one coupled atmosphere-ocean model in which the model was continuously nudged to the imposed SSTforcing. This talk provides an overview of the experiments and some initial results focusing on the responses to the leading patterns of annual mean SST variability consisting of a Pacific El Nino/Southern Oscillation (ENSO)-like pattern, a pattern that resembles the Atlantic Multi-decadal Oscillation (AMO), and a global trend pattern. One of the key findings is that all the AGCMs produce broadly similar (though different in detail) precipitation responses to the Pacific forcing pattern, with a cold Pacific leading to reduced precipitation and a warm Pacific leading to enhanced precipitation over most of the United States. While the response to the Atlantic pattern is less robust, there is general agreement among the models that the largest precipitation response over the U.S. tends to occur when the two oceans have anomalies of opposite sign. That is, a cold Pacific and warm Atlantic tend to produce the largest precipitation reductions, whereas a warm Pacific and cold Atlantic tend to produce the greatest precipitation enhancements. Further analysis of the response over the U.S. to the Pacific forcing highlights a number of

The role of surface heat fluxes in Southern Pacific and Atlantic Ocean SST anomalies associated with El Nino Southern Oscillation (ENSO) is studied using observation and ocean reanalysis products. A prominent dipole structure in SST anomaly is found with a positive (negative) anomaly center over south Pacific (65S-45S, 120W-70W) and negative (positive) one over south Atlantic (50S-30S, 30W-0E) during austral summer (DJF) of El Nino (LaNina). During late austral spring-early summer (OND) of El Nino (LaNina), anomalous northerly (southerly) meridional moisture transport and a positive (negative) sea level pressure anomaly induces a suppressed (enhanced) latent heat flux from the ocean surface over south Pacific. This in turn results in a shallower than normal mixed layer depth which further helps in development of the SST anomaly. Mixed layer thins further due to anomalous shortwave radiation during summer and a well developed SST anomaly evolves. The south Atlantic pole exhibits exactly opposite characteristics at the same time. The contribution from the surface heat fluxes to mixed layer temperature change is found to be dominant over the advective processes over both the basins. Net surface heat fluxes anomaly is also found to be maximum during late austral spring-early summer period, with latent heat flux having a major contribution to it. The anomalous latent heat fluxes between atmosphere and ocean surface play important role in the growth of observed summertime SST anomaly. Sea-surface height also shows similar out-of-phase signatures over the two basins and are well correlated with the ENSO related SST anomalies. It is also observed that the magnitude of ENSO related anomalies over the southern ocean are weaker in LaNina years than in El Nino years, suggesting an intensified tropics-high latitude tele-connection during warm phases of ENSO.

Influence of North Atlantic sea surface temperature (SST) anomalies on tropical Pacific SST anomalies is examined. Both summer and winter North Atlantic SST anomalies are negatively related to central-eastern tropical Pacific SST anomalies in the subsequent months varying from 5 to 13 months. In particular, when the North Atlantic is colder than normal in the summer, an El Nino event is likely to be initiated in the subsequent spring in the tropical Pacific. Associated with summer cold North Atlantic SST anomalies is an anomalous cyclonic circulation at low-level over the North Atlantic from subsequent October to April. Corresponded to this local response, an SST-induced heating over the North Atlantic produces a teleconnected pattern, similar to the East Atlantic/West Russia teleconnection. The pattern features two anticyclonic circulations near England and Lake Baikal, and two cyclonic circulations over the North Atlantic and near the Caspian Sea. The anticyclonic circulation near Lake Baikal enhances the continent northerlies, and strengthens the East-Asian winter monsoon. These are also associated with an off-equatorial cyclonic circulation in the western Pacific during the subsequent winter and spring, which produces equatorial westerly wind anomalies in the western Pacific. The equatorial westerly wind anomalies in the winter and spring can help initiate a Pacific El Nino event following a cold North Atlantic in the summer. (orig.)

We show that the climate phenomena of El Nino and La Nina arise naturally as states of macro-variables when our recent causal feature learning framework (Chalupka 2015, Chalupka 2016) is applied to micro-level measures of zonal wind (ZW) and sea surface temperatures (SST) taken over the equatorial band of the Pacific Ocean. The method identifies these unusual climate states on the basis of the relation between ZW and SST patterns without any input about past occurrences of El Nino or La Nina. The simpler alternatives of (i) clustering the SST fields while disregarding their relationship with ZW patterns, or (ii) clustering the joint ZW-SST patterns, do not discover El Nino. We discuss the degree to which our method supports a causal interpretation and use a low-dimensional toy example to explain its success over other clustering approaches. Finally, we propose a new robust and scalable alternative to our original algorithm (Chalupka 2016), which circumvents the need for high-dimensional density learning.

Multi year SST and NCEP/NCAR reanalyzed wind data were employed to study the impacts of El Nino on the Southeast Asian summer monsoon (SEASM). It was found that the impacts of El Nino on the SEASM differed distinctly from those on the East Asian summer monsoon (EASM) and the Indian summer monsoon (ISM). Composite analysis indicated that the "gear point" of coupling between the Indo monsoon circulation and the Pacific Walker circulation was located in the western margins of Southeast Asia when the developing stage of El Nino events covered the boreal summer. The anomalous circulations in the lower and upper troposphere and divergent circulation are all favorable for the strengthening of the SEASM during this period. Following the evolution of El Nino, the "gear point" of the two cells shifted eastward tothe central Pacific when the mature or decaying period of El Nino events covered the boreal summer. The anomalous circulations are favorable for the weakening of the SEASM. The anomalous indexes of intensity of SEASM accord well withthe above results. Additionally, the difference of SSTA patterns in the tropical Indo Pacific Ocean between the two stages of the El Nino may play an important role.

The interannual variability of the Asian Subtropical Westerly Jet (ASWJ) in boreal summer is investigated through the diagnosis of 54-year (1960-2013) NCEP/NCAR reanalysis data. The main characteristics of two leading empirical orthogonal function patterns of 200 hPa zonal wind anomalies are the meridional displacement and southwest-northeast tilting of ASWJ. The first leading mode has significant periods of 4.9 years, whereas the second mode has significant periods of 3.6 and 7.7 years, respectively. The two modes exhibit an equivalent barotropic structure, and are associated with a distinctive north-south and east-west dipole rainfall pattern in China, respectively. The positive phase of the first leading mode appears during El Nino developing phase, whereas the positive phase of the second mode occurs during La Nina decaying phase. A mechanism is put forth based on observational analysis and AGCM sensitivity experiments. The positive phase of the first mode is primarily driven by the combined effect of a cold SST anomaly (SSTA) in mid-latitude North Pacific and a warm SSTA in tropical Indian Ocean and Pacific. In response to the SSTA forcing, a zonally oriented north-south tropospheric temperature dipole is induced. While the tropospheric warming in the tropics arises from El Nino like heating, the tropospheric cooling in the mid-latitudes arises possibly from the local SSTA forcing. For the positive phase of the second mode, the upper-tropospheric anticyclonic vorticity anomaly in the east pole arises from local SSTA forcing in North Pacific, whereas the cyclonic anomaly in the west pole results from southeastward Rossby wave energy emanation from North Atlantic to East Asia.

El Nino events, characterized by anomalous warming in the eastern equatorial Pacific Ocean, have global climatic teleconnections and are the most dominant feature of cyclic climate variability on subdecadal timescales. Understanding changes in the frequency or characteristics of El Nino events in a changing climate is therefore of broad scientific and socioeconomic interest. Recent studies(1-5) show that the canonical El Nino has become less frequent and that a different kind of El Nino has b...

We present the evolution of oceanographic conditions off the western coast of South America between 1996 and 1999, including the cold periods of 1996 and 1998??9 and the 1997??8 El Nino, using satellite observations of sea level, winds, sea surface temperature (SST), and chlorophyll concentration. Following a period of cold SST and low sea levels in 1996, both were anomalously high between March 1997 and May 1998.

EL Nino is an abnormal warm situation in the Pacific Ocean which manifests once in a few years due to ocean-atmosphere interaction. It is much talked about inrecent times because it is believed to be'associated with floods, droughts, cyclones...

Full Text Available Banda sea is subjected to external force such as El Nino South Oscillation (ENSO, Indonesian Through Flow (ITF andMonsoon. All of these component Combined with Current System, caused sea dynamic. This study aimed to get further knowledge aboutBanda sea dynamic. Based on this phenomenon , this study was conducted with an hypothesis that sea level anomaly (SLA and seasufrace temperature (SST will decrease during ENSO event. Also that SLA and SST will seasonally change concerning with Monsoon.The pattern of current in eastern of Banda sea will be seasonally different concerning with monsoon while in western of Banda sea isalmost constant according to ITFThis research carried out in Banda Sea within the rectangular region from 122.42 E to 131.47 E , Latitude 03.47 S to 07.65 S.in period of 1996 to 2006 consist of northwest monsoon, southeast monsoon, 1st transitional month in April and 2nd transitional monthin October. Spatial analysis used to analyze annual and seasonal distribution of SST and SLA from satellite dataset, also by comparisonbetween wind data, ITF pathway and numerical model. SST derived from NOAA / AVHRR satellite data by applying MCSST algorithm,SLA derived from Topex/ Poseidon and Jason-1 Satellite data by applying Inverse distance weighted interpolation, while numerical modelderived from barothropic model using Princeton ocean model.Sea level anomaly and sea surface temperature is decrease according to ENSO event, such as descrease of SLA and SST duringENSO event in 1997 , 2002 and 2004. Sea level anomaly and sea surface temperature is change according to Monsoon that reverse every6 (six month. SST and SLA get maximum level during northwest monsoon in November to March and get Minimum during Southeastmonsoon in May to September. There are strong correlation coefficient between annual Sea level anomaly and annual Sea SurfaceTemperature with index value up to 0.817104. on the other side correlation coefficient between seasonal Sea

Decadal variability of the South China Sea (SCS) sea surface temperature (SST) during 1982-2014 is investigated using observations and ocean reanalysis datasets. The SCS SST shows an abrupt transition from a cold-to-warm regime in the late 1990s. Based on the long-term SST variability two epochs are defined, 1982-1996 and 2000-2014 as cold and warm regimes respectively, spanning on either side of the 1997-1999 SCS warming. Despite the occurrence of strong El Nino induced warming events, the SST anomalies tend to be negative in the cold regime. Conversely during the warm regime, the positive SST anomalies have dominated over the La Nina driven cooling events. The cold (warm) SST regime is marked by net heat gain (loss) by the SCS. The long-term variations of net surface heat flux are mainly driven by the latent heat flux anomalies while the short wave flux plays a secondary role. Low-frequency variability of the South China Sea throughflow (SCSTF) appears to be closely related to the SCS SST regime shift. The SCSTF shows reversing trends during the cold and warm epochs. The weakened SCSTF in the warm regime has promoted the SCS warming by limiting the outward flow of warm water from the SCS. Meanwhile, enhanced SCSTF during the cold regime acts as a cooling mechanism and lead to persistent negative SST anomalies. The change in trend of the SCSTF and SST regime shift coincides with the switching of pacific decadal oscillation from a warm to cold phase in the late 1990s.

The main objective of this article is to establish a new mechanism of ENSO, as a self-organizing and selfexcitation system, with two highly coupled processes. The first is the oscillation between the two mctastable warm (El Nino phase) and cold events (La Nina phase), and the second is the spatiotemporal oscillation of the sea surface temperature (SST) field. The symbiotic interplay between these two processes gives rises the climate variability associated with the ENSO, leads to both the random and deterministic features of the ENSO, and defines a new natural feedback mechanism, which drives the sporadic oscillation of the ENSO. The new mechanism is rigorously derived using a dynamic transition theory developed recently by the authors, which has also been successfully applied to a wide range of problems in nonlinear sciences.

An ocean data assimilation and forecast system for the Equatorial Pacific is presented. The Ensemble Kalman Filter is used to combine several types of real data with a reduced-gravity shallow-water model containing a simplified SST equation. A preliminary version of this assimilation system has been found in the past to produce skillful forecasts of Nino 3 and Nino 4 SST anomalies when artifical data obtained from model runs are used. The small size and simplicity of the model now allows us to experiment with different types of real data, ensemble sizes, assimilation frequency, etc. Forecasts are made by coupling a statistical atmosphere to the ocean model. We make a comparison between assimilation of subsurface temperature information and sea surface temperature and height into a model forced by observed winds, and assimilation of both ocean data and observed winds into the coupled model. The influence of model error can be studied by introducing changes to the model parameterizations or by comparing the difference in skill between the real data case and a twin experiment setup. The results are compared with the historical record of SST anomalies and will serve as a benchmark for the implementation of the Ensemble Kalman Filter with more elaborate models.

Recent studies have suggested that sea surface temperature (SST) is an important source of variability of the North Atlantic Oscillation (NAO). Here, we deal with four basic aspects contributing to this issue: (1) we investigate the characteristic time scales of this oceanic influence; (2) quantify the scale-dependent hindcast potential of the NAO during the twentieth century as derived from SST-driven atmospheric general circulation model (AGCM) ensembles; (3) the relevant oceanic regions are identified, corresponding SST indices are defined and their relationship to the NAO are evaluated by means of cross spectral analysis and (4) our results are compared with long-term coupled control experiments with different ocean models in order to ensure whether the spectral relationship between the SST regions and the NAO is an intrinsic mode of the coupled climate system, involving the deep ocean circulation, rather than an artefact of the unilateral SSTforcing. The observed year-to-year NAO fluctuations are barely influenced by the SST. On the decadal time scales the major swings of the observed NAO are well reproduced by various ensembles from the middle of the twentieth century onward, including the negative state in the 1960s and part of the positive trend afterwards. A six-member ECHAM4-T42 ensemble reveals that the SST boundary condition affects 25% of total decadal-mean and interdecadal-trend NAO variability throughout the twentieth century. The most coherent NAO-related SST feature is the well-known North Atlantic tripole. Additional contributions may arise from the southern Pacific and the low-latitude Indian Ocean. The coupled climate model control runs suggest only the North Atlantic SST-NAO relationship as being a true characteristic of the coupled climate system. The coherence and phase spectra of observations and coupled simulations are in excellent agreement, confirming the robustness of this decadal-scale North Atlantic air-sea coupled mode. (orig.)

The global north-south interhemispheric sea surface temperature (SST) difference experienced a pronounced and rapid decrease in the late 1960s, which has been linked to drying in the Sahel, South Asia, and East Asia. However, some basic questions about the interhemispheric SST shift remain unresolved, including its scale and whether the constituent changes in different basins were coordinated. In this study, we systematically investigate the spatial and temporal behavior of the late-1960s interhemispheric SST shift using ocean surface and subsurface observations. We also evaluate potential mechanisms using control and specific-forcing CMIP5 simulations. Using a regime shift detection technique, we identify the late-1960s shift as the most prominent in the historical observational SST record. We additionally examine the corresponding changes in upper-ocean heat content and salinity associated with the shift. We find that there were coordinated upper-ocean cooling and freshening in the subpolar North Atlantic, the region of the largest-magnitude SST decrease during the interhemispheric shift. These upper-ocean changes correspond to a weakened North Atlantic thermohaline circulation (THC). However, the THC decrease does not fully account for the rapid global interhemispheric SST shift, particularly the warming in the extratropical Southern Hemisphere.

A signature of El Nino-Southern Oscillation is found in the historical dataset of the Alaskan Tanana river breakups where the average ice breaking day is found to anticipate of about 3.4 days when conditioned over El Nino years. This results represents a statistically significant example of ENSO teleconnection on regions remote from tropical Pacific.

In this paper, by using ocean surface temperature data (COADS), the study is made of the characteristics of the monthly and annual changes of the SST in the tropical western Pacific and Indian Oceans, which have important influences on the climate change of the whole globe and the relation between ENSO(E1 Nino-Southern Oscillation) and the Antarctic ice area is also discussed. The result indicates that in the tropical western Pacific and the Indian Oceans the change of Sea Surface Temperture (SST) is conspicuous both monthly and armaully, and shows different change tendency between them. This result may be due to different relation in the vibration period of SST between the two Oceans. The better corresponding relationship is obvious in the annual change of SST in the tropical Indian Ocean with the occurrence El Nino and LaNlra. The change of the SST in the tropical western Pacific and the tropical Indian Oceans has a close relation to the Antarctic ice area, especially to the ice areas in the eastern-south Pole and Ross Sea, and its notable correlative relationship appears in 16 months when the SST of the tropical western Pacific and the Indian Oceans lag back the Antarctic ice area.

Near real-time interactive computer model has been developed to extract daily mean global Sea Surface Temperature (SST) values of 1440x720 pixels, each one covering 0.25° x0.25° lat-long area and SST anomalies from longer period means pertaining to any required oceanic grid size of interest. The core MATLAB code uses the daily binary files (3-day aggregate values) of global SST data (derived from TRMM/TMI-AQUA/AMSRE satellite sensors) available on near real-time basis through the REMSS/NASA website and converts these SSTs into global/regional maps and displays as well as digitised text data tables for further analysis. As demonstrated applications of the model, the SST data for the period between 2003-2009 has been utilised to study (a) SST anomalies before, during and after the occurrence of two great under-sea earthquakes of 26 December 2004 and 28 March 2005 near the western coast of Sumatra and (b) variation of pixel numbers with SSTs between 27-31° C within (i) Nino 4 region and (ii) a broader western Pacific region (say Nino-BP) affected by ENSO events before (January-May) and during (June-October) Monsoon onset/progress. Preliminary results of these studies have been published (Chakravarty, The Open Oceanography Journal, 2009 and Chakravarty, IEEE Xplore, 2009). The results of the SST-earthquake analysis indicate a small but consistent warming of 0.2-0.3° C in the 2° x2° grid area near the earthquake epicentre starting a week earlier to a week later for the event of 26 December 2004. The changes observed in SST for the second earthquake is also indicated but with less clarity owing to the mixing of land and ocean surfaces and hence less number of SST pixels available within the 2° x 2° grid area near the corresponding epicen-tre. Similar analysis for the same period of non-earthquake years did not show any such SST anomalies. These results have far reaching implications to use SST as a possible parameter to be monitored for signalling occurrence of

National Oceanic and Atmospheric Administration, Department of Commerce — The optimum interpolation (OI) sea surface temperature (SST) analysis is produced weekly on a one-degree grid. The analysis uses in situ and satellite SST's plus...

Discusses the nature and effects of the El Nino/Southern Oscillation phenomenon. Indicates that new understanding of the phenomenon from current data will provide a global view of climate that has never before been within reach. (JN)

Details the experiences of a teacher who spent a month on a National Oceanic and Atmospheric Administration (NOAA) ship. Reports observations of developing El Nino conditions and presents related classroom activities. (DDR)

Provides information on El Nino and the methods for investigating ancient climate record. Traces the rise and fall of the Andean empires focusing on the climatic forces that each empire (Tiwanaku, Wari, Moche, and Inca) endured. States that modern societies should learn from the experiences of these ancient civilizations. (CMK)

Provides information on El Nino and the methods for investigating ancient climate record. Traces the rise and fall of the Andean empires focusing on the climatic forces that each empire (Tiwanaku, Wari, Moche, and Inca) endured. States that modern societies should learn from the experiences of these ancient civilizations. (CMK)

We use a quantile-based bias correction technique and a multi-member ensemble of the atmospheric component of NCAR CCSM3 (CAM3) simulations to investigate the influence of sea surface temperature (SST) biases on future climate change projections. The simulations, which cover 1977-1999 in the historical period and 2077-2099 in the future (A1B) period, use the CCSM3-generated SSTs as prescribed boundary conditions. Bias correction is applied to the monthly time-series of SSTs so that the simulated changes in SST mean and variability are preserved. Our comparison of CAM3 simulations with and without SST correction shows that the SST biases affect the precipitation distribution in CAM3 over many regions by introducing errors in atmospheric moisture content and upper-level (lower-level) divergence (convergence). Also, bias correction leads to significantly different precipitation and surface temperature changes over many oceanic and terrestrial regions (predominantly in the tropics) in response to the future anthropogenic increases in greenhouse forcing. The differences in the precipitation response from SST bias correction occur both in the mean and the percent change, and are independent of the ocean-atmosphere coupling. Many of these differences are comparable to or larger than the spread of future precipitation changes across the CMIP3 ensemble. Such biases can affect the simulated terrestrial feedbacks and thermohaline circulations in coupled climate model integrations through changes in the hydrological cycle and ocean salinity. Moreover, biases in CCSM3-generated SSTs are generally similar to the biases in CMIP3 ensemble mean SSTs, suggesting that other GCMs may display a similar sensitivity of projected climate change to SST errors. These results help to quantify the influence of climate model biases on the simulated climate change, and therefore should inform the effort to further develop approaches for reliable climate change projection. (orig.)

The latest image from NASA's Jason oceanography satellite, taken during a 10-day collection cycle ending December 2, 2002, shows the Pacific dominated by two significant areas of higher-than-normal sealevel (warmer ocean temperatures). In the central equatorial Pacific, the large area of higher than normal sea surface heights(warmer than normal sea surface temperatures) associated with growing El Nino conditions has recently migrated eastward toward the coast of South America. Meanwhile, the influence of the 20- to 30-year larger than El Nino/La Nina pattern called the Pacific Decadal Oscillation continues to create warm, higher-than-normal sea-surface heights in the north Pacific that are connected in a warm horseshoe pattern with the western and southern Pacific. Sea-surface heights are a measure of how much heat is stored in the ocean below. This heat influences both present weather and future planetary climate events.The image shows red areas in the north Pacific and at the equator that are about 10 centimeters (4 inches) above normal; white areas indicate sea surface heights between 14 and 32 centimeters (6 to 13 inches) above normal. These regions contrast with the western tropical Pacific, where lower-than-normal sea levels (blue areas) have developed that are between 5 and 13 centimeters (2 and 5 inches) below normal, while purple areas range from 14 to 18 centimeters (6 to 7 inches) below normal. Along the equator, the red sea surface heights equate to sea surface temperature departures greater than one degree Celsius (two degrees Fahrenheit) and the white sea surface heights are sea surface temperatures 1.5 to 2.5 degrees Celsius(three to five degrees Fahrenheit) above normal.The U.S. portion of the Jason mission is managed by JPL for NASA's Earth Science Enterprise, Washington, D.C. Research on Earth's oceans using Jason and other space-based capabilities is conducted by NASA's Earth Science Enterprise to better understand and protect our home planet.

National Oceanic and Atmospheric Administration, Department of Commerce — The Oceanic Nino Index (ONI) is one of the primary indices used to monitor the El Nino-Southern Oscillation (ENSO). The ONI is calculated by averaging sea surface...

The mechanism of the locking of the El Nino event onset phase to boreal spring (from April to June)in an intermediate coupled ocean-atmosphere model is investigated. The results show that the seasonal variation of the zonal wind anomaly over the equatorial Pacific associated with the seasonal variation of the ITCZ is the mechanism of the locking in the model. From January to March of the El Nino year, the western wind anomaly over the western equatorial Pacific can excite the downwelling Kelvin wave that propagates eastward to the eastern and middle Pacific by April to June. From April to December of the year before the El Nino year, the eastern wind anomaly over the equatorial Pacific forces the downwelling Rossby waves that modulate the ENSO cycle. The modulation and the reflection at the western boundary modulate the time of the transition from the cool to the warm phase to September of the year before the El Nino year and cause the strongest downwelling Kelvin wave from the reflected Rossby waves at the western boundary to arrive in the middle and eastern equatorial Pacific by April to June of the El Nino year. The superposition of these two kinds of downwelling Kelvin waves causes the El Nino event to tend to occur from April to June.

Large submarine lava flows with apparent volumes exceeding 10 km3 have recently been imaged on the deep ocean floor in various parts of the Pacific by means of GLORIA and SeaMarc side-looking sonar surveys. Such flows may produce thermal anomalies large enough to perturb the cyclic processes of the ocean and could be a factor in the genesis of El Nino phenomena. We find that known volume rates of mid-ocean magma production could generate repetitive thermal anomalies as large as 10% of the average El Nino sea surface anomaly at intervals of about 5 years (the mean interval of El Nino events between 1935 and 1984). Likewise, estimated rates of eruption, cooling of lava on the seafloor, and transfer of heat to the near-surface environment could reasonably produce a thermal anomaly comparable to that associated with El Nino. Larger magmatic events, associated with fluctuations in the total magmatic power and seismicity along the East Pacific Rise, are possible at longer intervals and may explain the extreme size of some El Nino events, such as that of 1982-1983. -Authors

A steady state superconducting tokamak (SST-1) has been commissioned after the successful experimental and engineering validations of its critical sub-systems. During the ‘engineering validation phase’ of SST-1; the cryostat was demonstrated to be leak-tight in all operational scenarios, 80 K thermal shields were demonstrated to be uniformly cooled without regions of ‘thermal runaway and hot spots’, the superconducting toroidal field magnets were demonstrated to be cooled to their nominal operational conditions and charged up to 1.5 T of the field at the major radius. The engineering validations further demonstrated the assembled SST-1 machine shell to be a graded, stress-strain optimized and distributed thermo-mechanical device, apart from the integrated vacuum vessel being validated to be UHV compatible etc. Subsequently, ‘field error components’ in SST-1 were measured to be acceptable towards plasma discharges. A successful breakdown in SST-1 was obtained in SST-1 in June 2013 assisted with electron cyclotron pre-ionization in the second harmonic mode, thus marking the ‘first plasma’ in SST-1 and the arrival of SST-1 into the league of contemporary steady state devices. Subsequent to the first plasma, successful repeatable plasma start-ups with E ˜ 0.4 V m-1, and plasma current in excess of 70 kA for 400 ms assisted with electron cyclotron heating pre-ionization at a field of 1.5 T have so far been achieved in SST-1. Lengthening the plasma pulse duration with lower hybrid current drive, confinement and transport in SST-1 plasmas and magnetohydrodynamic activities typical to large aspect ratio SST-1 discharges are presently being investigated in SST-1. In parallel, SST-1 has uniquely demonstrated reliable cryo-stable high field operation of superconducting TF magnets in the two-phase cooling mode, operation of vapour-cooled current leads with cold gas instead of liquid helium and an order less dc joint resistance in superconducting magnet winding

Heading Abstract. A methodology is presented for making optimum use of the global sea surface temperature (SST) field for long lead prediction of the Indian summer monsoon rainfall (ISMR). To avoid the node phase of the biennial oscillation of El Nino Southern Oscillation (ENSO)-monsoon system and also to include the multiyear ENSO variability, the ISMR-SST relationship was examined from three seasons lag prior to the start of the monsoon season up to four years lag. First, a correlation analysis is used to identify the regions and seasonal lags for which SST is highly correlated with ISMR. The correlation patterns show a slow and consistent temporal evolution, suggesting the existence of SST oscillations that produce significant correlation even when no direct physical relationship between SST and ISMR, at such long lags, is plausible. As a second step, a strategy for selecting the best 14 predictors (hot spots of the global oceans) is investigated. An experimental prediction of ISMR is made using the SST anomalies in these 14 hot spots. The prediction is consistent for the 105 years (1875 to 1979) of the model development and the 22 years (1980 to 2001) of the model verification period (these last years were not included in the correlation analysis or in the computation of the regression model). The predicted values explain about 80% of the observed variance of ISMR in the model verification period. It is shown that, to a large extent, the behavior of the ensuing ISMR can be determined nine months in advance using SST only. The consistent and skillful prediction for more than a century is not a product of chance. Thus the anomalously strong and weak monsoon seasons are parts of longer period and broader scale circulation patterns, which result from interactions in the ocean-atmosphere coupled system over many seasons in the past. It is argued that despite the weakening of the ENSO-ISMR relationship in recent years, most of the variability of ISMR can still be

In this paper,the possible reason of Tibetan Plateau (TP) temperature increasing was investigated.An increase in Tmin (minimum temperature) plays a robust role in increased TP temperature,which is strongly related to SST over the warm pool of the western Pacific Ocean,the subtropical westerly jet stream (SWJ),and the tropical easterly upper jet stream (TEJ),and the 200-hPa zonal wind in East Asia.Composite analysis of the effects of SST,SWJ,and TEJ on pre- and post-abrupt changes in Ta (annual temperature) and Tmin over the TP shows remarkable differences in SST,SWJ,and TEJ.A lag correlation between Ta/Tmin,SST,and SWJ/TEJ shows that changes in SST occur ahead of changes in Ta/Tmin by approximately one to three seasons.Partial correlations between Ta/Tmin,SST,and SWJ/TEJ show that the effect of SWJ on Ta/Tmin is more significant than the effect of SST.Furthermore,simulations with a community atmospheric model (CAM3.0) were performed,showing a remarkable increase in Ta over the TP when the SST increased by 0.5°C.The main increase in Ta and Tmin in the TP can be attributed to changes in SWJ.A possible mechanism is that changes in SSTforce the TEJ to weaken,move south,and lead to increased SWJ and movement of SWJ northward.Finally,changes in the intensity and location of the SWJ cause an increase in Ta/Tmin.It appears that TP warming is governed primarily by coherent TEJ and SWJ wriations that act as the atmospheric bridges to remote SSTs in warm-pool forcing.

Kenya was affected by the El-Nino phenomena in 1997 which resulted in 1 billion U.S. dollars in property damage. El-Nino and Southern Oscillation (SO) produce ENSO, a Pacific Basin wide phenomenon that disrupts weather around the world. The social, political and economic impacts of El-Nino were examined by the author. While policymakers blamed the phenomena for the damages, the author suggests that there are ways in which developing countries contribute to global warming and argued that poverty, bad governance and high illiteracy rate added to the environmental crisis in Africa. The phenomenon was blamed for causing Kenya's road network to collapse as did the coffee industry. Displaced people suffered from diseases related to floods and lack of food and water supply. This paper did not address the issue of whether there is a relationship between El-Nino and global warming, but rather emphasized the fact that Africa can only claim a place in global conservation efforts once it has addressed social issues such as poverty reduction strategies. 10 refs.

The response of the equatorial Pacific Ocean to heat fluxes of equal amplitude but opposite sign is investigated using the Community Earth System Model (CESM). Results show a strong asymmetry in SST changes. In the eastern equatorial Pacific (EEP), the warming responding to the positive forcing exceeds the cooling to the negative forcing; while in the western equatorial Pacific (WEP), it is the other way around and the cooling surpasses the warming. This leads to a zonal dipole asymmetric structure, with positive values in the east and negative values in the west. A surface heat budget analysis suggests that the SST asymmetry is mainly resulted from the oceanic horizontal advection and vertical entrainment, with both of their linear and nonlinear components playing a role. For the linear component, its change appears to be more significant over the EEP (WEP) in the positive (negative) forcing scenario, favoring the seesaw pattern of the SST asymmetry. For the nonlinear component, its change acts to warm (cool) the EEP (WEP) in both scenarios, also favorable for the development of the SST asymmetry. Additional experiments with a slab ocean confirm the dominant role of ocean dynamical processes for this SST asymmetry. The net surface heat flux, in contrast, works to reduce the SST asymmetry through its shortwave radiation and latent heat flux components, with the former being related to the nonlinear relationship between SST and convection, and the latter being attributable to Newtonian damping and air-sea stability effects. The suppressing effect of shortwave radiation on SST asymmetry is further verified by partially coupled overriding experiments.

In this lesson plan, the city of Malibu (CA) is at the mercy of the weather phenomenon El Nino. The press secretary for the Mayor of Malibu recognizes an opportunity to turn this potential natural disaster into a re-election campaign. A task force will be assembled to protect the lives and property of the community. Students role play members of…

The Hadley sea-surface temperature (HadSST) dataset is investigated for the interval 1871-2008. The purpose of this investigation is to determine the degree of success in identifying and characterizing El Nino (EN) southern (ENSO) extreme events, both EN and La Nina (LN) events. Comparisons are made against both the Southern Oscillation Index for the same time interval and with published values of the Oceanic Nino Index for the interval since 1950. Some 60 ENSO extreme events are identified in the HadSST dataset, consisting of 33 EN and 27 LN events. Also, preferential associations are found to exist between the duration of ENSO extreme events and their maximum anomalous excursion temperatures and between the recurrence rate for an EN event and the duration of the last known EN event. Because the present ongoing EN is a strong event, it should persist 11 months or longer, inferring that the next EN event should not be expected until June 2012 or later. Furthermore, the decadal sum of EN-related months is found to have increased somewhat steadily since the decade of 1920-1929, suggesting that the present decade (2010-2019) possibly will see about 3-4 EN events, totaling about 37 +/- 3 EN-related months (i.e., months that meet the definition for the occurrence of an EN event).

The impact of diurnal SST coupling and vertical oceanic resolution on the simulation of the Indian Summer Monsoon (ISM) and its relationships with El Nino-Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) events are studied through the analysis of four integrations of a high resolution Coupled General Circulation Model (CGCM), but with different configurations. The only differences between the four integrations are the frequency of coupling between the ocean and atmosphere for the Sea Surface Temperature (SST) parameter (2 vs. 24 h coupling) and/or the vertical oceanic resolution (31 vs. 301 levels) in the CGCM. Although the summer mean tropical climate is reasonably well captured with all the configurations of the CGCM and is not significantly modified by changing the frequency of SST coupling from once to twelve per day, the ISM-ENSO teleconnections are rather poorly simulated in the two simulations in which SST is exchanged only once per day, independently of the vertical oceanic resolution used in the CGCM. Surprisingly, when 2 h SST coupling is implemented in the CGCM, the ISM-ENSO teleconnection is better simulated, particularly, the complex lead-lag relationships between the two phenomena, in which a weak ISM occurs during the developing phase of an El Nino event in the Pacific, are closely resembling the observed ones. Evidence is presented to show that these improvements are related to changes in the characteristics of the model's El Nino which has a more realistic evolution in its developing and decaying phases, a stronger amplitude and a shift to lower frequencies when a 2-hourly SST coupling strategy is implemented without any significant changes in the basic state of the CGCM. As a consequence of these improvements in ENSO variability, the lead relationships between Indo-Pacific SSTs and ISM rainfall resemble the observed patterns more closely, the ISM-ENSO teleconnection is strengthened during boreal summer and ISM rainfall power spectrum

Taking the main land of Europe as the region to be studied, the potential of the new satellite gravity technique: satellite-to-satellite tracking (SST) and improving the accuracy of regional gravity field model with the SST models are investigated. The drawbacks of these models are discussed. With GPM98C as the reference, the gravity anomaly residuals of several other models, the latest SST global gravity field models (EIGEN series and GGM series), were computed and compared. The results of the comparison show that in the selected region, some systematic errors with periodical properties exist in the EIGEN and GGM's S series models in the high degree and order. Some information that was not shown in the classic gravity models is detected in the low and middle degree and order of EIGEN and GGM's S series models. At last, the effective maximum degrees and orders of SST models are suggested.

Numerical simulations of the remotely forced ocean response to westerly wind bursts prior to and during the 1991 - 1992 El Nino are examined; the models are forced by wind stress from the U.S. Navy's atmospheric global operational analysis/forecast system. The study focuses on (1) the relative response of the first and second internal modes to a single episode of westerly bursts; (2) the role of westerly bursts in producing the eastern Pacific sea level variations from October 1990 to February 1992; and (3) the relative importance of the remotely forced sea level responses generated by central and western Pacific wind anomalies. The simulation use the Naval Research Laboratory global multilayer formulation; the suite of experiments includes hydrodynamic simulations that use both one- and three- active-layer reduced gravity models as well as an experiment that also includes thermodynamic effects. The models are executed from January 1, 1990, to March 1, 1992, a period that includes 10 significant westerly wind bursts or burst clusters and the 1991 - 1992 El Nino event. The numerical experiments reveal an ability to accurately simulate the eastern Pacific sea level variations during this period. In response to a single burst, the three-layer hydrodynamic simulation reveals that the second internal mode Kelvin wave yields a sea level change at the eastern boundary that is approximately one third that of the first mode and a surface velocity signature that is equivalent to the first mode. During the onset of the El Nino event the inclusion of higher modes also produces a more realistic representation of the observed eastern boundary sea level signal. Furthermore, by comparing the model response to particular wind bursts with the observed sea level at Baltra, Galapagos, a value of 2.5 - 2.6 m/s is suggested as the most appropriate mean speed for the first internal mode Kelvin wave during the onset phase. A scenario for the onset of the 1991 - 1992 El Nino is given.

Satellite measurements of both cloud vertical structure and cloud-radiative forcing have been used to show that during the strong 1997/98 El Nino there was a substantial change in cloud vertical structure over the tropical Pacific Ocean. Relative to normal years, cloud altitudes were lower in the western portion of the Pacific and higher in the eastern portion. The reason for these redistributions was a collapse of the Walker circulation and enhanced large-scale upward motion over the eastern Pacific, both caused by the lack of a zonal sea surface temperature gradient during El Nino. It is proposed that these cloud structure changes, which significantly impact satellite measurements of the tropical Pacific's radiation budget, would serve as one useful means of testing cloud-climate interactions in climate models.

Examination of the decadal variation of the number of El Nino onsets and El Nino-related months for the interval 1950-2008 clearly shows that the variation is better explained as one expressing normal fluctuation and not one related to global warming. Comparison of the recurrence periods for El Nino onsets against event durations for moderate/strong El Nino events results in a statistically important relationship that allows for the possible prediction of the onset for the next anticipated El Nino event. Because the last known El Nino was a moderate event of short duration (6 months), having onset in August 2006, unless it is a statistical outlier, one expects the next onset of El Nino probably in the latter half of 2009, with peak following in November 2009-January 2010. If true, then initial early extended forecasts of frequencies of tropical cyclones for the 2009 North Atlantic basin hurricane season probably should be revised slightly downward from near average-to-above average numbers to near average-to-below average numbers of tropical cyclones in 2009, especially as compared to averages since 1995, the beginning of the current high-activity interval for tropical cyclone activity.

Midwinter storm track response to zonal variations in midlatitude sea surface temperatures (SSTs) has been investigated using an atmospheric general circulation model under aquaplanet and perpetual-January conditions. Zonal wavenumber-1 SST variations with a meridionally confined structure are placed at various latitudes. Having these SST variations centered at 30°N leads to a zonally localized storm track, while the storm track becomes nearly zonally uniform when the same SSTforcing is moved farther north at 40° and 50°N. Large (small) baroclinic energy conversion north of the warm (cold) SST anomaly near the axis of the storm track (near 40°N) is responsible for the large (small) storm growth. The equatorward transfer of eddy kinetic energy by the ageostrophic motion and the mechanical damping are important to diminish the storm track activity in the zonal direction.Significant stationary eddies form in the upper troposphere, with a ridge (trough) northeast of the warm (cold) SST anomaly at 30°N. Heat and vorticity budget analyses indicate that zonally localized condensational heating in the storm track is the major cause for these stationary eddies, which in turn exert a positive feedback to maintain the localized storm track by strengthening the vertical shear near the surface. These results indicate an active role of synoptic eddies in inducing deep, tropospheric-scale response to midlatitude SST variations. Finally, the application of the model results to the real atmosphere is discussed.

Most of CMIP5 models projected a weakened Walker circulation in tropical Pacific, but what causes such change is still an open question. By conducting idealized numerical simulations separating the effects of the spatially uniform sea surface temperature (SST) warming, extra land surface warming and differential SST warming, we demonstrate that the weakening of the Walker circulation is attributed to the western North Pacific (WNP) monsoon and South America land effects. The effect of the uniform SST warming is through so-called "richest-get-richer" mechanism. In response to a uniform surface warming, the WNP monsoon is enhanced by competing moisture with other large-scale convective branches. The strengthened WNP monsoon further induces surface westerlies in the equatorial western-central Pacific, weakening the Walker circulation. The increase of the greenhouse gases leads to a larger land surface warming than ocean surface. As a result, a greater thermal contrast occurs between American Continent and equatorial Pacific. The so-induced zonal pressure gradient anomaly forces low-level westerly anomalies over the equatorial eastern Pacific and weakens the Walker circulation. The differential SST warming also plays a role in driving low-level westerly anomalies over tropical Pacific. But such an effect involves a positive air-sea feedback that amplifies the weakening of both east-west SST gradient and Pacific trade winds.

This teaching unit provides materials and information about the effects of El Nino on people, the economy, and nature around the world. It is important for students to know the impact El Nino has had on the world. The unit presents information that builds student's interest in other environmental phenomena as well. This unit offers information on…

This teaching unit provides materials and information about the effects of El Nino on people, the economy, and nature around the world. It is important for students to know the impact El Nino has had on the world. The unit presents information that builds student's interest in other environmental phenomena as well. This unit offers information on…

Pastoral del Nino is transforming children's lives in rural Paraguay. Part of Pastoral Social (Catholic Social Services), Pastoral del Nino's primary focus is to bring "vida en abundancia" (the abundant life) to families by ensuring that mothers survive childbirth and children reach their first birthdays. In addition, the organization…

The sensitivity of the global atmospheric and oceanic response to sea surface temperature anomaly (SSTA) throughout the South China Sea (SCS) is investigated using the Fast Ocean-Atmosphere Model (FOAM). Forced by a warming SST, the experiment explicitly demonstrates that the responses of surface air temperature (SAT) and SST exhibit positive anomalous center over SCS and negative anomalous center over the Northern Pacific Ocean (NPO). The atmospheric response to the warm SST anomalies is characterized by a barotropical anomaly in middle-latitude, leading to a weak subtropical high in summer and a weak Aleutian low in winter. Accordingly, Indian monsoon and eastern Asian monsoon strengthen in summer but weaken in winter as a result of wind convergence owing to the warm SST. It is worth noting that the abnormal signals propagate poleward and eastward away in the form of Rossby Waves from the forcing region, which induces high pressure anomaly. Owing to action of the wind-driven circulation, an anomalous anti-cyclonic circulation is induced with a primary southward current in the upper ocean. An obvious cooling appears over the North Pacific, which can be explained by anomalous meridional cold advection and mixing as shown in the analysises of heat budget and other factors that affect SST.

Cold water in the deep Pacific can be drawn up to the surface (or west warm water drifts eastwards ) because strong tide increases the mixing of seawater both in vertical and horizontal. In this way greenhouse effect is decreased or increased by means of absorbing (or releasing) CO2. Therefore, La Nina cold event (or El Nino warm event) may occur,which is caused by wanning - up or cooling - down air above the ocean. Volcanic action at sea bottom is also controlled by strong tide.

Moored current, temperature, salinity, and pressure data were collected at three sites that transect the narrow continental shelf offshore of Davenport, CA, starting in August 1996 and continuing to the spring of 1998. This data set allowed a comparison of oceanographic conditions prior to (8/96-3/97) and during (8/97-3/98) the last major El Nin??o. During this El Nin??o, mean temperatures over the 8-month time period were about 3??C warmer than during the prior year at all of the sites. Correlations between near-surface and near-bottom temperatures, and between near-surface temperature and wind stress decreased during the El Nin??o compared to conditions the year before. The mean alongshore currents were more strongly poleward during El Nin??o at sites over the mid-shelf and near the shelf break. There was a general tendency for the energy in alongshore currents to move toward lower frequencies during the El Nin??o, particularly at the sites farther offshore. The processes that forced the shelf flows changed in relative importance throughout the study. The local alongshore wind stress was less important in driving shelf currents during the El Nin??o when much of the wind-induced upwelling was confined to less than 5 km of the coast. The observed strong poleward shelf currents on the mid- to outer-shelf were not clearly tied to local forcing, but were remotely driven, most likely by slope currents. The response of the Davenport shelf to an El Nin??o event may differ from other areas since the shelf is narrow, the wind forcing is weaker than areas to the north and south, and the shelf may be at times isolated by fronts that form at strong upwelling centers. In the winter, strong storm-related winds are important in driving currents at periods not only in the synoptic wind band, but also for periods on the order of 20 d and longer.

Full Text Available The tropical Pacific exerts a major effect on the global climate system and might have driven large extra-tropical climate change. We present a 320 kyr high resolution UK'37-sea surface temperature (SST record from core MD052928 (11°17.26' S, 148°51.60' E, water depth 2250 m located off southeastern Papua New Guinea (PNG, in the western tropical Pacific. The age model of the core is based on AMS 14C dating of planktic foraminifers and correlation of benthic to the LR04 stack. The UK'37-SST ranges from 26.5 to 29 °C, showing glacial–interglacial and millennial variations. We assess the phase of the MD052928 UK'37-SST as part of a synthesis of five other SST records from the tropical Pacific at the precession, obliquity, and eccentricity bands. The SST records can be separated into two groups when considering SST phase relative to changes in orbital forcing, ice volume and greenhouse gases (GHGs. SST maxima at open-ocean sites within primary equatorial current systems occur between obliquity maxima and methane (CH4 maxima but early relative to ice volume minima and CO2 maxima at the obliquity band. In contrast, SST maxima at continental margin sites change are in phase with ice minima and CO2 maxima, likely influenced by the slow response of continental ice sheets and GHGs. At the precession band, the early group located on the Warm Pool area indicates a direct influenced by the local insolation, and with the similar phase progress as the obliquity band. These results indicate that the decreased high-low latitudes insolation gradient and increasing low latitude local insolation resulting in tropical Pacific SST rise. Higher SST would supply more moisture resulting in increased CH4 in the tropical wetlands. This promotes increasing CO2 and deglaciation leading to increase continental and continental margin surface temperatures.

For the first two weeks in June, the surface winds and sea surface temperatures across the Pacific Ocean began to display an all-too-familiar pattern. Normally, the trade winds in the equatorial Pacific blow from east to west and push warm surface waters from the eastern Pacific westward. As is indicated by the arrows displaying wind speed and direction in the above Quick Scatterometer (QuikScat) satellite data, the trade winds stopped and in some cases reversed course across the equatorial Pacific in early June. Consequently, the waters in the eastern Pacific grew warmer than usual. If this trend continued or intensified, another El Nino would have settled in by fall 2002 and rainfall and atmospheric circulation patterns would have begun to change across North and South America. However, in the later half of June conditions returned to normal. Scientists hope that satellite data from QuikScat will help them to study and even forecast future El Nino events. Launched aboard the SeaWinds satellite in 1999, the QuickScat instrument essentially sends out high frequency radio waves to detect the frothiness of ocean water. Since choppy ocean water is created almost solely by the surface winds blowing across the ocean, scientists can obtain an accurate measure of wind speed and direction from these data. Image courtesy NASA JPL Air-Sea Interaction and Climate Team

This Topex/Poseidon image of sea-surface heights was taken during a 10-day collection cycle ending August 7, 2002. Sea-surface heights are a measure of how much heat is stored in the ocean below to influence future planetary climate events. Since May 2001, there have been a series of warm Kelvin waves--eastward-moving ocean waves that cross the equatorial Pacific in about two months. A sizable one arrived at the South American coast last February, raising the ocean temperature by 2 degrees Celsius (3.6 degrees Fahrenheit) and triggering the National Oceanic and Atmospheric Administration's forecast for a mild El Nino in 2002. There was another wave in June, followed by the current large pool of warm water in the tropical Pacific that is now moving toward the coast of South America at a speed of 215 kilometers (134 miles) a day and will arrive there in three to four weeks, raising ocean temperatures. Scientists will continue to monitor the Pacific closely for further signs of El Nino formation and intensity.

Full Text Available Moderate Resolution Imaging Spectroradiometers (MODIS and Visible Infrared Imaging Radiometer Suite (VIIRS radiometers, flown onboard Terra/Aqua and Suomi National Polar-orbiting Partnership (S-NPP/Joint Polar Satellite System (JPSS satellites, are capable of providing superior sea surface temperature (SST imagery. However, the swath data of these multi-detector sensors are subject to several artifacts including bow-tie distortions and striping, and require special pre-processing steps. VIIRS additionally does two irreversible data reduction steps onboard: pixel aggregation (to reduce resolution changes across the swath and pixel deletion, which complicate both bow-tie correction and destriping. While destriping was addressed elsewhere, this paper describes an algorithm, adopted in the National Oceanic and Atmospheric Administration (NOAA Advanced Clear-Sky Processor for Oceans (ACSPO SST system, to minimize the bow-tie artifacts in the SST imagery and facilitate application of the pattern recognition algorithms for improved separation of ocean from cloud and mapping fine SST structure, especially in the dynamic, coastal and high-latitude regions of the ocean. The algorithm is based on a computationally fast re-sampling procedure that ensures a continuity of corresponding latitude and longitude arrays. Potentially, Level 1.5 products may be generated to benefit a wide range of MODIS and VIIRS users in land, ocean, cryosphere, and atmosphere remote sensing.

Using seasonal hindcasts of six different models participating in the North American Multimodel Ensemble project, the trend of the predicted sea surface temperature (SST) in the tropical Pacific for 1982-2014 at each lead month and its temporal evolution with respect to the lead month are investigated for all individual models. Since the coupled models are initialized with the observed ocean, atmosphere, land states from observation-based reanalysis, some of them using their own data assimilation process, one would expect that the observed SST trend is reasonably well captured in their seasonal predictions. However, although the observed SST features a weak-cooling trend for the 33-year period with La Niña-like spatial pattern in the tropical central-eastern Pacific all year round, it is demonstrated that all models having a time-dependent realistic concentration of greenhouse gases (GHG) display a warming trend in the equatorial Pacific that amplifies as the lead-time increases. In addition, these models' behaviors are nearly independent of the starting month of the hindcasts although the growth rates of the trend vary with the lead month. This key characteristic of the forecasted SST trend in the equatorial Pacific is also identified in the NCAR CCSM3 hindcasts that have the GHG concentration for a fixed year. This suggests that a global warming forcing may not play a significant role in generating the spurious warming trend of the coupled models' SST hindcasts in the tropical Pacific. This model SST trend in the tropical central-eastern Pacific, which is opposite to the observed one, causes a developing El Niño-like warming bias in the forecasted SST with its peak in boreal winter. Its implications for seasonal prediction are discussed.

Complex networks have been used intensively to investigate the flow and dynamics of many natural systems including the climate system. Here, we develop a percolation based measure, the order parameter, to study and quantify climate networks. We find that abrupt transitions of the order parameter usually occur $\\sim$1 year before El Ni\\~{n}o ~ events, suggesting that they can be used as early warning precursors of El Ni\\~{n}o. Using this method we analyze several reanalysis datasets and show the potential for good forecasting of El Ni\\~{n}o. The percolation based order parameter exhibits discontinuous features, indicating possible relation to the first order phase transition mechanism.

Forces are at work all around us. Discover what a force is, and different kinds of forces that work on contact and at a distance. We use simple language and vocabulary to make this invisible world easy for students to ""see"" and understand. Examine how forces ""add up"" to create the total force on an object, and reinforce concepts and extend learning with sample problems.

Atmospheric response to SST variability was estimated using generalized equilibrium feedback analysis (GEFA) in the SST EOF space with synthesis data from an idealized climate model. Results show that the GEFA atmospheric response to the leading SST EOF modes is much more accurate and robust than the GEFA feedback matrix in physical space. Therefore, GEFA provides a practical method for assessing atmospheric response to large-scale SST anomalies in terms of the leading EOFs.

The inter-annual relationship between the boreal winter Arctic Oscillation (AO) and summer sea surface temperature (SST) over the western tropical Indian Ocean (TIO) for the period from 1979 to 2015 is investigated. The results show that the January-February-March AO is significantly correlated with the June-July-August SST and SST tendency. When both El Niño/Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) variance are excluded, the winter AO is significantly correlated with the regional mean SST of the western TIO (40° -60° E and 10° S-10° N), r=0.71 . The multi-month SST tendency, i.e., the SST difference of June-July-August minus April-May, is correlated with the winter AO at r=0.75 . Composite analysis indicates similar warming over the western TIO. Two statistical models are established to predict the subsequent summer's SST and SST tendency. The models use the winter AO, the winter ENSO and the autumn-winter IOD indexes as predictors and explain 65 and 62 % of the variance of the subsequent summer's SST and SST tendency, respectively. Investigation of the regional air-sea fluxes and oceanic dynamics reveals that the net surface heat flux cannot account for the warming, whereas the oceanic Rossby wave plays a predominant role. During positive AO winters, the enhanced Arabian High causes stronger northern winds in the northern Indian Ocean and leads to anomalous cross-equatorial air-flow. The Ekman pumping in association with the anomalous wind stress curl in the central TIO generates a significantly deeper thermocline and above-normal sea surface height at 60° -75° E and 5° -10° S. The winter AO-forced Rossby wave propagates westward and arrives at the western coast in summer, resulting in the significant SST increase. Forced by the observed winter AO-related wind stress anomalies over the Indian Ocean, the ocean model reasonably reproduces the Rossby wave as well as the resulting surface ocean warming over the western TIO in the

... fullstory_162611.html Did El Nino Weather Give Zika a Boost? Climate phenomenon could have helped infection- ... might have aided the explosive spread of the Zika virus throughout South America, a new study reports. ...

Full Text Available Paddy and maize are two important food crops in Indonesia and mainly produced in Java Island. This research aimed to know the impact of El Nino and La Nina on paddy and maize farmer’s supply in Java. Cross sectional data from four provinces in Java was combined with time series data during 1987-2006. Paddy supply was estimated using log model, while maize supply used autoregressive model; each was estimated using two types of regression function. First, it included dummy variable of El Nino and La Nina to know their influence into paddy and maize supply. Second, Southern Oscillation Index was used to analyze the supply changing when El Nino or La Nina occur. The result showed that El Nino and La Nina did not influence paddy supply, while La Nina influenced maize supply in Java. Maize supply increased when La Nina occurred.

Predictive skill for El Niño in the equatorial eastern Pacific across a range of forecast models declined in the early 21st century relative to what was achieved in the late 20th century. This decline coincided with a reduction of El Niño variability in the eastern Pacific and a shift in Pacific climate to an enhanced east-west surface temperature gradient and stronger trade winds in the central Pacific, which has previously been associated with the recent hiatus in global surface warming. It is an outstanding question as to whether this shift in climate at the end of the 20th century acted to weaken El Niño variability, hence predictability, or whether El Niño variability weakened by chance thus reducing predictability but in so doing resulted in the shift in climate. Using seasonal forecast sensitivity experiments with the Australian Bureau of Meteorology coupled model POAMA2.4, the shift to intensified east-west surface temperature gradient and stronger central Pacific trade winds is shown to weaken the ocean-atmosphere feedback that amplify eastern Pacific El Niño, thus resulting in weaker variability that is less predictable. This weakened coupling helps explain the fitful behaviour and challenges for forecasting the non-developing El Niño in early 2014. In contrast, the Pacific mean state appears to have swung to a more favourable condition for promoting El Nino toward the end of 2014, thus supporting stronger development of El Nino in 2015.

It is well established that sea surface temperature anomaly (SSTA) is one of the principle factors that have significant influence on global climate variability. Due to large mass and great thermal capacity of the oceans, oceanic conditions change relatively slowly and dominant patterns are thus easy to detect. Most of the current research on SSTA make use of PCA methods like EOF or SVD. Though such methods are effective in reducing dimensions, it is always hard to give a physical interpretation of the results and difficult to distinguish the minor eigenvectors from noises. Instead of finding patterns, we put forward a framework for the direct prediction of SSTAs, using a sparse approximation method, the least absolute shrinkage and selection operator (lasso), to reduce the noises in global SST observation. Global SSTA time series in 5°×5° resolution were used to fit each target SSTA vector and the lasso method was utilized to avoid over-fitting. Taking the Nino 3.4 Index as an example, the predictability of the lasso model was studied and the results showed a relatively satisfying prediction skill in terms of correlation coefficient and root-mean-square error compared with the results obtained from LDEO 5. Moreover, by taking other climate variables into consideration, we discovered a stable relation between the Nino 3.4 Index and the sea-ice extent anomaly in South Pole at a lead time of around 2 years. In addition, the bootstrapping method was used to resample the coefficients in the sparse regression model so that we could study their statistical property. 14 regressors were reserved suggesting 10 potential indices which have relatively strong relations with the Nino 3.4 Index. Some of the potential indices corresponded well to known climate indices while the rest indicated an undiscovered index in tropical oceans of eastern South America. In conclusion, the lasso method approved its feasibility in climate prediction at a relatively low computation cost, and

The paper presents the results of a detailed design, evaluation and trade-off of a potential European Space Surveillance and Tracking (SST) system architecture. The results have been produced in study phase 1 of the on-going "CO-II SSA Architectural Design" project performed by the Astrium consortium as part of ESA's Space Situational Awareness Programme and are the baseline for further detailing and consolidation in study phase 2. The sensor network is comprised of both ground- and space-based assets and aims at being fully compliant with the ESA SST System Requirements. The proposed ground sensors include a surveillance radar, an optical surveillance system and a tracking network (radar and optical). A space-based telescope system provides significant performance and robustness for the surveillance and tracking of beyond-LEO target objects.

Detrended, modelled first leaf dates for 856 sites across North America for the period 1900-2008 are used to examine how the El Nino Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO) separately and together might influence the timing of spring. Although spring (mean March through April) ENSO and PDO signals are apparent in first leaf dates, the signals are not statistically significant (at a 95% confidence level (p Nino and positive PDO conditions. An analysis of the spatial distributions of first leaf dates for separate and combined ENSO/PDO conditions features a northwest-southeast dipole that is significantly (at p <0.05) different than the distributions for neutral conditions. The nature of the teleconnection between Pacific SST's and first leaf dates is evident in comparable composites for detrended sea level pressure (SLP) in the spring months. During positive ENSO/PDO, there is an anomalous flow of warm air from the southwestern US into the northwestern US and an anomalous northeasterly flow of cold air from polar regions into the eastern and southeastern US. These flow patterns are reversed during negative ENSO/PDO. Although the magnitudes of first leaf date departures are not necessarily significantly related to ENSO and PDO, the spatial patterns of departures are significantly related to ENSO and PDO. These significant relations and the long-lived persistence of SSTs provide a potential tool for forecasting the tendencies for first leaf dates to be early or late.

textabstractAlthough in situ hybridization has been used to examine the distribution of messenger RNA for somatostatin receptor subtypes (sst) in human tumors, the cellular localization of sst1 and sst2A receptors has not been reported. In this study, we describe the ce

The Sea Level Anomaly-Torque (SLAT, relative to a reference location in the Pacific Ocean), which means the total torque of the gravity forces of sea waters with depths equal to the Sea Level Anomaly (SLA) in the tropical Pacific Ocean, is defined in this study. The time series of the SLAT from merged altimeter data (1993-2003) had a great meridional variation during the 1997-1998 El Ni(n)o event. By using historical upper layer temperature data (1955-2003) for the tropical Pacific Ocean, the temperature-based SLAT is also calculated and the meridional variation can be found in the historical El Ni(n)o events (1955-2003), which suggests that the meridional shifts of the sea level anomaly are also intrinsic oscillating modes of the El Ni(n)o cycles like the zonal shifts.

The response of El Nino and Southern Oscillation (ENSO)-like variability to global warming varies comparatively between the two different climate system models, i.e., the Meteorological Research Institute (MRI) and Geophysical Fluid Dynamics Laboratory (GFDL) Coupled General Circulation Models (CGCMs). Here, we examine the role of the simulated upper ocean temperature structure in the different sensitivities of the simulated ENSO variability in the models based on the different level of CO{sub 2} concentrations. In the MRI model, the sea surface temperature (SST) undergoes a rather drastic modification, namely a tendency toward a permanent El Nino-like state. This is associated with an enhanced stratification which results in greater ENSO amplitude for the MRI model. On the other hand, the ENSO simulated by GFDL model is hardly modified although the mean temperature in the near surface layer increases. In order to understand the associated mechanisms we carry out a vertical mode decomposition of the mean equatorial stratification and a simplified heat balance analysis using an intermediate tropical Pacific model tuned from the CGCM outputs. It is found that in the MRI model the increased stratification is associated with an enhancement of the zonal advective feedback and the non-linear advection. In the GFDL model, on the other hand, the thermocline variability and associated anomalous vertical advection are reduced in the eastern equatorial Pacific under global warming, which erodes the thermocline feedback and explains why the ENSO amplitude is reduced in a warmer climate in this model. It is suggested that change in stratification associated with global warming impacts the equatorial wave dynamics in a way that enhances the second baroclinic mode over the gravest one, which leads to the change in feedback processes in the CGCMs. Our results illustrate that the upper ocean vertical structure simulated in the CGCMs is a key parameter of the sensitivity of ENSO

The standard deviation of the central Pacific sea surface temperature anomaly (SSTA) during the period from October to February shows that the central Pacific SSTA variation is primarily due to the occurrence of the Central Pacific El Ni(n)o (CP-El Ni(n)o)and has a connection with the subtropical air-sea interaction in the northeastern Pacific.After removing the influence of the Eastern Pacific El Ni(n)o,an S-EOF analysis is conducted and the leading mode shows a clear seasonal SSTA evolving from the subtropical northeastern Pacific to the tropical central Pacific with a quasi-biennial period.The initial subtropical SSTA is generated by the wind speed decrease and surface heat flux increase due to a north Pacific anomalous cyclone.Such subtropical SSTA can further influence the establishment of the SSTA in the tropical central Pacific via the wind-evaporation-SST (WES) feedback.After established,the central equatorial Pacific SSTA can be strengthened by the zonal advective feedback and thermocline feedback,and develop into CP-El Ni(n)o.However,as the thermocline feedback increases the SSTA cooling after the mature phase,the heat flux loss and the reversed zonal advective feedback can cause the phase transition of CP-El Ni(n)o.Along with the wind stress variability,the recharge (discharge) process occurs in the central (eastern) equatorial Pacific and such a process causes the phase consistency between the thermocline depth and SST anomalies,which presents a contrast to the original recharge/discharge theory.

The atmospheric stationary wave response to a midlatitude sea surface temperature (SST) anomaly is examined with an idealized general circulation model (GCM) as well as steady linear model, in a similar way as Ting and Held, for a tropical SST anomaly. The control climate of the GCM is zonally symmetric; this symmetric climate is then perturbed by a monopole SST anomaly centered at 40[degrees]N. Two experiments, with SST anomalies of opposite sign, have been conducted. The stationary response is roughly linear in the sign of the SST anomaly, despite the fact that precipitation shows strong nonlinearity. The linear model, which is in exact linearization of the GCM equations in use, when forced by anomalous heating and transients, reproduces the GCM's stationary response excellently. The low-level transient eddy heat fluxes act to damp the lower level temperature signal. When this damping effect is mimicked by a horizontal thermal diffusion in the linear model, the response to the diabatic heating alone gives a reasonably good simulation of the GCm's anomaly; the effect of the anomalous transient momentum fluxes is relatively small. A crude latent heat parameterization scheme, using an evaporation anomaly that is proportional to the mean air-sea surface moisture difference and including the effects of mean moisture advection, is developed. When the perturbation mixing ratio is approximated by assuming fixed relative humidity and by linearizing the Clausius-Clapeyron equation, the linear model's response, utilizing this latent heat parameterization scheme, gives a useful fit to the GCM's anomalous flow. 22 refs., 94 figs.

Using a compilation of the most recent, high-resolution proxy data from the tropics, and a state-of-the-art climate reconstruction technique (RegEM iTTLS; Emile-Geay et al, submitted), we reconstruct sea-surface temperature (SST) in the central equatorial Pacific (NINO3.4 region) over the past millennium. Using frozen network experiments and pseudoproxy validation, the reconstruction is found skillful back to 1150 C.E., with inevitable amplitude reduction before 1500 C.E. due to the paucity of proxy predictors. Despite this caveat, wavelet coherency analysis reveals a marked anticorrelation between solar forcing (as estimated from cosmogenic isotope concentrations; Bard et al., 2007; Steinhilber et al., 2009) and the reconstructed NINO3.4 in the ~sim205-year spectral range (DeVries cycle). The phase angle between both signals is 156 ± 33o in this range, indicating that periods of high solar irradiance coincide with cool conditions in the NINO3.4 region, with time lag of 14 ± 19 years. We find this result robust to the reconstruction method, estimate of solar forcing, or analysis method used to estimate the phasing. We then discuss the implication of this result for the response of tropical Pacific climate to radiative forcing. While the anti-phasing seems to favor the ``ocean dynamical thermostat'' hypothesis of Clement et al [1996], this feedback appears subdued in most IPCC-class coupled general circulation models (CGCMs), where it is almost completely compensated by changes in the Pacific trade winds, linked to changes in the vertical structures of atmospheric moisture and temperature (Knutson & Manabe 1995; Held & Soden 2006; Vecchi et al. 2006). If the reconstruction is correct that past NINO3.4 SSTs have varied out of phase with solar irradiance on bicentennial scales, this would pose a new challenge both for CGCM simulations and for our understanding of the equatorial Pacific response to radiative forcing Clement, A. C., Seager, R., Cane, M. A., and Zebiak

The El Ni\\~no-Southern Oscillation (ENSO) is a mode of interannual variability in the coupled equatorial ocean/atmosphere Pacific. El Ni\\~no describes a state in which sea surface temperatures in the eastern Pacific increase and upwelling of colder, deep waters diminishes. El Ni\\~no events typically peak in boreal winter, but their strength varies irregularly on decadal time scales. There were exceptionally strong El Ni\\~no events in 1982-83, 1997-98 and 2015-16 that affected weather on a global scale. Widely publicized forecasts in 2014 predicted that the 2015-16 event would occur a year earlier. Predicting the strength of El Ni\\~no is a matter of practical concern due to its effects on hydroclimate and agriculture around the world. This paper presents a new robust mechanism limiting the predictability of strong ENSO events: the existence of an irregular switching between an oscillatory state that has strong El Ni\\~no events and a chaotic state that lacks strong events, which can be induced by very weak seas...

Highlights: • SST-1 TF power supply is 12 pulse SCR converter circuit. • TF power supply protection, measurement and control scheme are explained. • Quench, emergency and normal shot process is explained and results of SST-1 campaigns are shown. • Dynamic control of TF current. • The paper shows the results of last ten SST-1 campaigns. - Abstract: SST-1 TF power supply provides the direct current for the required magnetic field of TF coil. TF power supply includes transformer, 12-pulse converter, bus bar, water-cooled cable, protection and measuring equipments, and isolator, VME DAC system and GUI software. TF power supply is operated through GUI software built in TCL/Tk. VME DAC system monitors the parameters, provides On/Off commands, voltage and current references and initiates predefined reference to emergency shutdown. The emergency shutdown is hardwired to TF power supply from central control. During quench power supply converter opens DCCB and dump resistor is connected in the circuit and VME DAC system acquires bus bar voltage, dump voltage and dump current. Operation of TF power supply also requires monitoring of SCR and transformer temperature and water flow rate of water-cooled cable during high current long pulse shot. Before start up of TF power supply a quench simulation is performed to check the readiness of protection. This paper describes pre startup operation, normal shot operation, emergency and quench process, dynamic control and complete shutdown operation of TF power supply.

Today, El Nino refers to the extreme warming episodes of the globally effective, coupled ocean-atmospheric interaction commonly known as ENSO (i.e., "El Nino-Southern Oscillation"). Concerning its observed decadal frequency and severity, El Nino during the 1990's has often been regarded as being anomalous. Results of analysis reported herein; however, appear to mitigate this belief.

Today, El Nino refers to the extreme warming episodes of the globally effective, coupled ocean-atmospheric interaction commonly known as ENSO (i.e., "El Nino-Southern Oscillation"). Concerning its observed decadal frequency and severity, El Nino during the 1990's has often been regarded as being anomalous. Results of analysis reported herein; however, appear to mitigate this belief.

I describe the Cohen-Walker-Witteborn (CWW) network of absolute calibration stars built to support ground-based, airborne, and space-based sensors, and how they are used to calibrate instruments on the SPITZER Space Telescope (SST and Japan's AKARI (formerly ASTRO-F), and to support NASA's planned MidEx WISE (the Wide-field Infrared Survey Explorer). All missions using this common calibration share a self-consistent framework embracing photometry and low-resolution spectroscopy. CWW also underpins COBE/DIRBE several instruments used on the Kuiper Airborne Observatory ({KAO}), the joint Japan-USA ``IR Telescope in Space" (IRTS) Near-IR and Mid-IR spectrometers, the European Space Agency's IR Space Observatory (ISO), and the US Department of Defense's Midcourse Space eXperiment (MSX). This calibration now spans the far-UV to mid-infrared range with Sirius (one specific Kurucz synthetic spectrum) as basis, and zero magnitude defined from another Kurucz spectrum intended to represent an ideal Vega (not the actual star with its pole-on orientation and mid-infrared dust excess emission). Precision 4-29 μm radiometric measurements on MSX validate CWW's absolute Kurucz spectrum of Sirius, the primary, and a set of bright K/MIII secondary standards. Sirius is measured to be 1.0% higher than predicted. CWW's definitions of IR zero magnitudes lie within 1.1% absolute of MSX measurements. The US Air Force Research Laboratory's independent analysis of on-orbit {MSX} stellar observations compared with emissive reference spheres show CWW primary and empirical secondary spectra lie well within the ±1.45% absolute uncertainty associated with this 15-year effort. Our associated absolute calibration for the InfraRed Array Camera (IRAC) on the SST lies within ˜2% of the recent extension of the calibration of the Hubble Space Telescope's STIS instrument to NICMOS (Bohlin, these Proceedings), showing the closeness of these two independent approaches to calibration.

Empirical orthogonal function (EOF) analysis reveals a co-variability of Sea surface temperatures (SSTs) in the Southern Hemisphere (0°-60°S).In the South Indian and Atlantic Oceans,there is a subtropical dipole pattern slanted in the southwest-northeast direction.In the South Pacific Ocean,a meridional tripole structure emerges,whose middle pole co-varies with the dipoles in the South Indian and Atlantic Oceans and is used in this study to track subtropical Pacific variability.The South Indian and Atlantic Ocean dipoles and the subtropical Pacific variability are phase-locked in austral summer.On the inter-decadal time scales,the dipoles in the South Indian and Atlantic Oceans weaken in amplitude after 1979/1980.No such weakening is found in the subtropical South Pacific Ocean.Interestingly,despite the reduced amplitude,the correlation of the Indian Ocean and Atlantic dipoles with El Ni(n)o and Southern Oscillation (ENSO) are enhanced after 1979/1980.The same increase in correlation is found for subtropical South Pacific variability after 1979/1980.These inter-decadal modulations imply that the Southem Hemisphere participates in part of the climate shift in the late 1970s.The correlation between Southern Hemisphere SST and ENSO reduces after 2000.

... Bureau of Industry and Security Arturo Guillermo Nino, Inmate Number 04908-379, FCI Beaumont Low, Federal..., in the U.S. District Court, Western District of Texas, Arturo Guillermo Nino (``Nino''), was...)) (``AECA''). Specifically, Nino was convicted of intentionally and knowingly conspiring with persons known...

Full Text Available Spatial correlations in the annual rainfall anomalies are analyzed using principle component analyses (PCA. Cross correlation analysis and composites are used to measure the influence of sea surface temperatures anomalies (SSTAs in the tropical Atlantic and tropical Pacific Ocean with the seasonal rainfall in Suriname. The spatial and time variability in rainfall is mainly determined by the meridional movement of the Inter-tropical Convergence Zone (ITCZ. Rainfall anomalies tend to occur fairly uniformly over the whole country. In December-January (short wet season, there is a lagged correlation with the SSTAs in the Pacific region (clag3Nino1+2=-0.63. The strongest correlation between the March-May rainfall (beginning long wet season and the Pacific SSTAs is found with a correlation coefficient of ckNino1+2=0.59 at lag 1 month. The June-August rainfall (end part of long wet season shows the highest correlation with SSTAs in the TSA region and is about c=-0.52 for lag 0. In the September-November long dry season there is also a lagged correlation with the TSA SSTAs of about clag3=0.66. The different correlations and predictors can be used for seasonal rainfall predictions.

) High-Resolution SST Pilot Project (GHRSST-PP) science team cate- gorised them under five kinds of SSTs (Donlon and the GHRSST-PP science team 2005). They are, interface SST, skin SST, sub-skin SST, SST at depth and foundation SST. The satellite based... measurements report the ‘skin SST’ (at a depth of few micrometers) and most of the in situ measure- ments report the ‘SST at depth’ (at depths of few cm to 1.0–5.0 m). The SST at depth is also simply referred as ‘bulk’ SST. Following this categorisa- tion...

Highlights: • An account of MHD activity in the plasma of SST-1 • Observation of MHD instabilities with mode m = 2, n = 1 in SST-1 plasma. • MHD instabilities study of characteristic growth time, growth rate of island and island width etc. in SST-1 plasma. - Abstract: Steady State Superconducting Tokamak (SST-1) is a medium size Tokamak in operation at the Institute for Plasma Research, India. SST-1 has been consistently producing plasma currents in excess of 60 kA, with plasma durations above 400 ms and a central magnetic field of 1.5 T over last few experimental campaigns of 2014. Investigation of these experimental data suggests the presence of MHD activity in the SST-1 plasma. Further analysis clearly explains the behavior of MHD instabilities observed (i.e. tearing modes with m = 2, n = 1), estimating the growth rate and the island width in the SST-1 plasma. Poloidal magnetic field and Toroidal magnetic field fluctuations in SST-1 are observed using Mirnov coils. Onsets of disruptions in connection with MHD activities have been correlated with other diagnostics such as ECE, Density and Hα etc. The observations have been cross compared with the theoretical calculations and are found to be in good agreement.

Coffee price volatility was extreme in 1997. With no obvious drought or freezing conditions in major growing countries, market analysts blamed El Nino. Alternatively, economic theory implies that commodity price volatility should be high when inventories are low. We analyze and test these two hypotheses

El Nino is a complex periodic oceanographic event that occurs off the west coast of South America, adversely affecting climate not only in the local area but in other regions of the world. There is evidence that the equatorial regions hold the key to predicting this economically destructive phenomenon. (Author/BB)

The Ninos Especiales Outreach Training Project was a 3-year federally funded project to provide information, training, and evaluation related to a culturally sensitive, family-focused model of early intervention services for infants with severe disabilities and their families of Puerto Rican heritage. Implementation occurred through three major…

The effects of SST anomalies on the interannual and intraseasonal variability of the Asian summer monsoon have been studied by multivariate statistical analyses of 850-hPa wind and rainfall fields simulated in a set of ensemble integrations of the ECMWF atmospheric GCM, referred to as the PRISM experiments. The simulations used observed SSTs (PRISM-O), covering 9 years characterised by large variations of the ENSO phenomenon in the 1980's and the early 1990's. A parallel set of simulations was also performed with climatological SSTs (PRISM-C), thus enabling the influence of SSTforcing on the modes of interannual and intraseasonal variability to be investigated. As in observations, the model's interannual variability is dominated by a zonally-oriented mode which describes the north-south movement of the tropical convergence zone (TCZ). This mode appears to be independent of SSTforcing and its robustness between the PRISM-O and PRISM-C simulations suggests that it is driven by internal atmospheric dynamics. O...

Full Text Available Epidemics of konzo have occurred during severe droughts in parts of east, central, and southern Africa since the 1920s. Occurrence is attributed to exposure to cyanide from poorly processed cassava foods, the sole source of calories when other food crops fail. El Nino, the warm phase of the El Nino-Southern Oscillation (ENSO, induces severe droughts in the geographical areas of Africa where epidemics of konzo occur. Climate regimes are determined by modes of Pacific Decadal Oscillation, which modulates the ENSO. Study was done to determine the relationship of konzo epidemics to climate regimes and phases of ENSO, and to propose a model to explain while konzo epidemics do not occur in all drought affected areas. Data of all konzo epidemics in the past century and in DR Congo from 1974–1996, and indices of ENSO and PDO from 1915 to 2014 were obtained. Konzo epidemics were mapped to phases of ENSO and PDO. Wavelet spectral and wavelet spectral coherence analysis of climate indices and konzo epidemics were done. All konzo epidemics of the past century occurred during warm climate regimes. Of 19 warm phases of ENSO from 1974–1996 in DR Congo, 17 were coupled to konzo epidemics, while of 4 cold phases of ENSO, 1was coupled to konzo epidemic, odds ratio 26 (95 % CI, 2–378. Global spectral of ENSO and konzo showed dominant periodicity of 5 years, while spectograms showed significant periodicities and coherence between 3–6 years. Spatial distribution of konzo is restricted to the area of maximal impact of El Nino on precipitation in Africa. El Nino is the underlying cause of konzo epidemics. Control of konzo epidemics requires management of the impact of El Nino on agriculture in areas where the population depends on cassava as sole source of calories during droughts. There is the need to develop forecast models of changes in cassava production to predict likely periods of konzo epidemics.

Highlights: ► Air leaks developed during ongoing SST-1 cooldown campaign were detected online using RGA. ► The presence of N{sub 2} and O{sub 2} gases with the ratio of their partial pressures with ∼3.81:1 confirmed the air leaks. ► Baking of SST-1 was done efficiently by flowing hot N{sub 2} gas in C-channels welded on inner surfaces without any problem. ► In-house fabricated demountable bull nose couplers were demonstrated for high temperature and pressure applications. ► Cryopumping effect was observed when liquid helium cooled superconducting magnets reached below 63 K. -- Abstract: Vacuum chambers of Steady State Superconducting (SST-1) Tokamak comprises of the vacuum vessel and the cryostat. The plasma will be confined inside the vacuum vessel while the cryostat houses the superconducting magnet systems (TF and PF coils), LN{sub 2} cooled thermal shields and hydraulics for these circuits. The vacuum vessel is an ultra-high (UHV) vacuum chamber while the cryostat is a high-vacuum (HV) chamber. In order to achieve UHV inside the vacuum vessel, it would be baked at 150 °C for longer duration. For this purpose, U-shaped baking channels are welded inside the vacuum vessel. The baking will be carried out by flowing hot nitrogen gas through these channels at 250 °C at 4.5 bar gauge pressure. During plasma operation, the pressure inside the vacuum vessel will be raised between 1.0 × 10{sup −4} mbar and 1.0 × 10{sup −5} mbar using piezoelectric valves and control system. An ultimate pressure of 4.78 × 10{sup −6} mbar is achieved inside the vacuum vessel after 100 h of pumping. The limitation is due to the development of few leaks of the order of 10{sup −5} mbar l/s at the critical locations of the vacuum vessel during baking which was confirmed with the presence of nitrogen gas and oxygen gas with the ratio of ∼3.81:1 indicating air leak. Similarly an ultimate vacuum of 2.24 × 10{sup −5} mbar is achieved inside the cryostat. Baking of the

The relationship between cloud amount and sea surface temperature (SST) over Western Tropical Pacific cloudy regions during TOGA COARE is investigated based on hourly grid simulation data from a two-dimensional coupled ocean-cloud resolving atmosphere model. The model is forced by the large-scale vertical velocity and zonal wind observed and derived from TOGA COARE for a 50-day period. The cloud amount becomes smaller when the ocean surface gets warmer, which is similar to previous relations obtained from observational analyses. As SST increases, the atmospheric temperature increases whereas the surface sensible heat flux decreases. The atmospheric water vapor is not sensitive to SST whereas the surface evaporation flux decreases as SST increases. These indicate that the oceanic effects do not play an important role in determining atmospheric heat and water vapor budgets. The cold atmosphere pro-duces a larger amount of ice clouds that cover a larger area than the warm atmosphere does. The large amounts of ice clouds lead to cooling of the ocean surface through reflecting large amount of solar radiation back to the space. Thus, the negative correlation between the cloud amount and SST only accounts for the important atmospheric effects on the ocean.

In most parts of the global ocean, the magnitude of the long-term linear trend in sea surface temperature (SST) is much smaller than the amplitude of multi-scale internal variation. One can thus use a specific period in a much longer record to arbitrarily determine the sign of long-term trend, which is statistically significant, in regional SST. This could lead to a controversial conclusion on how global SST responded to the anthropogenic forcing in the recent history. In this study, the uncertainty in the linear trend due to multi-scale internal variation is theoretically investigated. It is found that the "estimated" trend will not change its sign only when its magnitude is greater than a theoretical threshold that scales the influence from the multi-scale internal variation. Otherwise, the sign of the "estimated" trend may depend on the period used. The new criterion is found to be superior over the existing methods when the de-trended time series is dominated by the oscillatory term. Applying this new criterion to a global SST reconstruction from 1881 to 2013 reveals that the influences from multi-scale internal variation on the sign of "estimated" linear trend cannot be excluded in most parts of the Pacific, the southern Indian Ocean and the northern Atlantic; therefore, the warming or/and cooling trends found in these regions cannot be interpreted as the consequences of anthropogenic forcing. It's also suggested that the recent hiatus can be explained by combined uncertainty from internal variations at the interannual and decadal time scales.

The role of halted "baroclinic modes" in the central equatorial Pacific is analyzed. It is found that dominant anomaly signals corresponding to "baroclinic modes" occur in the upper layer of the equatorial Pacific, in a two-and-a-half layer oceanic model, in assimilated results of a simple OGCM and in the ADCP observation of TAO. A second "baroclinic mode" is halted in the central equatorial Pacific corresponding to a positive SST anomaly while the first "baroclinic mode" propagates eastwards in the eastern equatorial Pacific. The role of the halted second "baroclinic mode" in the central equatorial Pacific is explained by a staged ocean-atmosphere interaction mechanism in the formation of El Ni(n)o: the westerly bursts in boreal winter over the western equatorial Pacific generate the halted second "baroclinic mode" in the central equatorial Pacific, leading to the increase of heat content and temperature in the upper layer of the central Pacific which induces the shift of convection from over the western equatorial Pacific to the central equatorial Pacific; another wider, westerly anomaly burst is induced over the western region of convection above the central equatorial Pacific and the westerly anomaly burst generates the first "baroclinic mode"propagating to the eastern equatorial Pacific, resulting in a warm event in the eastern equatorial Pacific.The mechanism presented in this paper reveals that the central equatorial Pacific is a key region in detecting the possibility of ENSO and, by analyzing TAO observation data of ocean currents and temperature in the central equatorial Pacific, in predicting the coming of an El Ni(n)o several months ahead.

Past studies have shown that the use of coarse resolution SST products such as from the real-time global (RTG) SST analysis[1] or other coarse resolution once-a-day products do not properly portray the diurnal variability of fluxes of heat and moisture from the ocean that drive the formation of low level clouds and precipitation over the ocean. For example, the use of high resolution MODIS SST composite [2] to initialize the Advanced Research Weather Research and Forecast (WRF) (ARW) [3] has been shown to improve the prediction of sensible weather parameters in coastal regions [4][5}. In an extend study, [6] compared the MODIS SST composite product to the RTG SST analysis and evaluated forecast differences for a 6 month period from March through August 2007 over the Florida coastal regions. In a comparison to buoy data, they found that that the MODIS SST composites reduced the bias and standard deviation over that of the RTG data. These improvements led to significant changes in the initial and forecasted heat fluxes and the resulting surface temperature fields, wind patterns, and cloud distributions. They also showed that the MODIS composite SST product, produced for the Terra and Aqua satellite overpass times, captured a component of the diurnal cycle in SSTs not represented in the RTG or other one-a-day SST analyses. Failure to properly incorporate these effects in the WRF initialization cycle led to temperature biases in the resulting short term forecasts. The forecast impact was limited in some situations however, due to composite product inaccuracies brought about by data latency during periods of long-term cloud cover. This paper focuses on the forecast impact of an enhanced MODIS/AMSR-E composite SST product designed to reduce inaccuracies due data latency in the MODIS only composite product.

The human somatostatin receptor 3 (sst3) is expressed in about 50% of all neuroendocrine tumors and hence a promising target for multireceptor somatostatin analogs. The sst3 receptor is unique among ssts in that it exhibits a very long intracellular C-terminal tail containing a huge number of potential phosphate acceptor sites. Consequently, our knowledge about the functional role of the C-terminal tail in sst3 receptor regulation is very limited. Here, we have generated a series of phosphorylation-deficient mutants that enabled us to determine crucial sites for its agonist-induced β-arrestin mobilization, internalization, and down-regulation. Based on this information, we generated phosphosite-specific antibodies for C-terminal Ser(337)/Thr(341), Thr(348), and Ser(361) that enabled us to investigate the temporal patterns of sst3 phosphorylation and dephosphorylation. We found that the endogenous ligand somatostatin induced a rapid and robust phosphorylation that was completely blocked by the sst3 antagonist NVP-ACQ090. The stable somatostatin analogs pasireotide and octreotide promoted clearly less phosphorylation compared with somatostatin. We also show that sst3 phosphorylation occurred within seconds to minutes, whereas dephosphorylation of the sst3 receptor occurred at a considerable slower rate. In addition, we also identified G protein-coupled receptor kinases 2 and 3 and protein phosphatase 1α and 1β as key regulators of sst3 phosphorylation and dephosphorylation, respectively. Thus, we here define the C-terminal phosphorylation motif of the human sst3 receptor that regulates its agonist-promoted phosphorylation, β-arrestin recruitment, and internalization of this clinically relevant receptor.

The role of sub-seasonal western and central Pacific surface zonal wind variability in the evolution of El Niño sea surface temperature anomaly (SSTA) is examined. The surface wind structure and atmospheric convection variability of tropical Pacific westerly wind events (WWEs) is described. The average tropical Pacific SSTA variability following and in the absence of equatorial WWEs is examined over the period 1986-1998. The surface wind structure of the Madden-Julian Oscillation is examined (MJO), along with relationships between the MJO and WWEs. The response of an ocean general circulation model (OGCM) to composite MJO and WWE surface wind stress forcing is explored. WWEs can be classified into eight types based on the location of the maximum zonal wind anomalies. WWEs are found to be compact in space and time, exhibiting little translation during their lifetime. Typical scales for WWEs are derived over the period 1986-1995. It is found that certain WWE types exhibit significant seasonality, and some have a significant correlation with the Troup Southern Oscillation Index. In the absence of equatorial WWEs, tropical Pacific SSTA tends to remain at or return towards climatology. Following equatorial WWEs, tropical Pacific SSTA warms towards or remains at El NiNo type conditions. WWEs are significantly associated with atmospheric convection. The MJO surface wind stress anomaly fields exhibit two regimes in the equatorial Pacific. In the western equatorial Pacific there are both easterly and westerly anomalies with the westerlies dominating, in the central and eastern equatorial Pacific the main anomalies are easterlies. The WWEs which occur during the MJO are modulated by the convective variability of the MJO. West- of-dateline WWEs exhibit a strong relationship to tropical cyclone activity. Following a composite MJO, the tropical Pacific SSTA in the OGCM does not tend to warm; the composite MJO does not provide a simple mechanism for El Niño waveguide warming

The characteristics of the El-Nino Southern Oscillation (ENSO) simulated in free integrations using two versions of the Seoul National University (SNU) ocean-atmosphere coupled global climate model (CGCM) are examined. A revised version of the SNU CGCM is developed by incorporating a reduced air-sea coupling interval (from 1 day to 2 h), a parameterization for cumulus momentum transport, a minimum entrainment rate threshold for convective plumes, and a shortened auto-conversion time scale of cloud water to raindrops. With the revised physical processes, lower tropospheric zonal wind anomalies associated with the ENSO-related sea surface temperature anomalies (SSTA) are represented with more realism than those in the original version. From too weak, the standard deviation of SST over the eastern Pacific becomes too strong in the revised version due to the enhanced air-sea coupling strength and intraseasonal variability associated with ENSO. From the oceanic side, the stronger stratification and the shallower-than-observed thermocline over the eastern Pacific also contribute to the excessive ENSO. The impacts of the revised physical processes on the seasonal predictability are investigated in two sets of the hindcast experiment performed using the two versions of CGCMs. The prediction skill measured by anomaly correlation coefficients of monthly-mean SSTA shows that the new version has a higher skill over the tropical Pacific regions compared to the old version. The better atmospheric responses to the ENSO-related SSTA in the revised version lead to the basin-wide SSTA maintained and developed in a manner that is closer to observations. The symptom of an excessively strong ENSO of the new version in the free integration is not prominent in the hindcast experiment because the thermocline depth over the eastern Pacific is maintained as initialized over the arc of time of the hindcast (7 months). (orig.)

Full Text Available The Hawaiian Islands are an ideal location to study the response of tropical forests to climate variability because of their extreme isolation in the middle of the Pacific, which makes them especially sensitive to El Niño-Southern Oscillation (ENSO. Most research examining the response of tropical forests to drought or El Niño have focused on rainforests, however, tropical dry forests cover a large area of the tropics and may respond very differently than rainforests. We use satellite-derived Normalized Difference Vegetation Index (NDVI from February 2000-February 2009 to show that rainforests and dry forests in the Hawaiian Islands exhibit asynchronous responses in leaf phenology to seasonal and El Niño-driven drought. Dry forest NDVI was more tightly coupled with precipitation compared to rainforest NDVI. Rainforest cloud frequency was negatively correlated with the degree of asynchronicity (Delta(NDVI between forest types, most strongly at a 1-month lag. Rainforest green-up and dry forest brown-down was particularly apparent during the 2002-003 El Niño. The spatial pattern of NDVI response to the NINO 3.4 Sea Surface Temperature (SST index during 2002-2003 showed that the leeward side exhibited significant negative correlations to increased SSTs, whereas the windward side exhibited significant positive correlations to increased SSTs, most evident at an 8 to 9-month lag. This study demonstrates that different tropical forest types exhibit asynchronous responses to seasonal and El Niño-driven drought, and suggests that mechanisms controlling dry forest leaf phenology are related to water-limitation, whereas rainforests are more light-limited.

This image displays wind measurements taken by the satellite-borne NASA Scatterometer (NSCAT) during the last 10 days of May 1997, showing the relationship between the ocean and the atmosphere at the onset of the 1997-98 El Nino condition. The data have helped scientists confirm that the event began as an unusual weakening of the trade winds that preceded an increase in sea surface temperatures. The arrows represent wind speed and direction while the colors indicate sea surface temperature. The sea surface temperatures were measured by the Advanced Very High Resolution Radiometer, a joint mission of NASA and the National Oceanographic and Atmospheric Administration (NOAA). The trade winds normally blow from east to west, but the small arrows in the center of the image show the winds have changed direction and are blowing in the opposite direction. The areas shown in red are above normal sea surface temperatures -- along the equator, off the west coast of the U.S., and along the west coast of Mexico. This image also shows an unusual low pressure system with cyclonic (counterclockwise) circulation near the western North American coast. NSCAT also observed that winds associated with this circulation pattern branched off from the equator, bypassed Hawaii, and brought heat and moisture from the tropical ocean towards San Francisco, in what is often called the 'pineapple express.'

The temperatures in different zones in the world do not show significant changes due to El-Nino except when measured in a restricted area in the Pacific Ocean. We find, in contrast, that the dynamics of a climate network based on the same temperature records in various geographical zones in the world is significantly influenced by El-Nino. During El-Nino many links of the network are broken, and the number of surviving links comprises a specific and sensitive measure for El-Nino events. While during non El-Nino periods these links which represent correlations between temperatures in different sites are more stable, fast fluctuations of the correlations observed during El-Nino periods cause the links to break.

Climate change simulations robustly show a warming hole in the sub-polar North Atlantic that results from slowing of the AMOC countering the global warming signal. Here we investigate how the distinct SST spatial structures, which include a sharpening of the Gulf Stream SST gradients, influence climate change in the NA sector in winter. For this we analyse the RCP8.5 scenario simulation of the MPI Earth System Model. Additional sensitivity experiments with the atmospheric model component, ECHAM5, are performed to deconstruct the effect of the local spatial structure of the SST change from those arising from large-scale warming of the ocean, remote SST pattern changes and changed radiative forcings. The MPI model simulation shows a signifcant decrease in precipitation to the south of the GS extension region in the future, despite a strong increase in underlying SST. While directly to the north there is a significant increase in precipitation. These distinct features in the precipitation response over the North Atlantic result from the local SST. Over the Gulf Stream, the differential structure of the precipitation changes reflects the changes of the local SST gradients there. Over the subpolar gyre the increase in precipitation is partly suppressed. In this region the Subpolar Gyre the weakened AMOC causes a SST warming, that is much weaker than the warming other regions of the ocean show at the same latitude. The large-scale response, which includes the overall increase in precipitation over the NA is due to the overall warming, remote SSTs and/or directly connected to the radiative forcing.

National Oceanic and Atmospheric Administration, Department of Commerce — A daily, global Sea Surface Temperature (SST) data set is produced at 1-km (MUR, or Multi-scale ultra-high resolution Temperature) by the JPL sciengists Drs. Mike...

National Aeronautics and Space Administration — JPL OurOcean Portal: A daily, global Sea Surface Temperature (SST) data set is produced at 1-km (also known as ultra-high resolution) by the JPL ROMS (Regional Ocean...

National Oceanic and Atmospheric Administration, Department of Commerce — A new sea surface temperature (SST) analysis on a centennial time scale is presented. The dataset starts in 1850 with monthly 1x1 means and is periodically updated....

National Oceanic and Atmospheric Administration, Department of Commerce — This archive covers two high resolution sea surface temperature (SST) analysis products developed using an optimum interpolation (OI) technique. The analyses have a...

The temperature of the sea surface has been identified as an important parameter of the natural environment, governing processes that occur in the upper ocean. This paper focuses on the analysis of the Sea Surface Temperature (SST) anomalies at the greater area of Cyprus. For that, SST data derived from MODerate-resolution Imaging Spectroradiometer (MODIS) instrument on board both Aqua and Terra sun synchronous satellites were used. A four year period was chosen as a first approach to address and describe this phenomenon. Geographical Information Systems (GIS) has been used as an integrated platform of analysis and presentation in addition of the support of MATLAB®. The methodology consists of five steps: (i) Collection of MODIS SST imagery, (ii) Development of the digital geo-database; (iii) Model and run the methodology in GIS as a script; (iv) Calculation of SST anomalies; and (v) Visualization of the results. The SST anomaly values have presented a symmetric distribution over the study area with an increase trend through the years of analysis. The calculated monthly and annual average SST anomalies (ASST) make more obvious this trend, with negative and positive SST changes to be distributed over the study area. In terms of seasons, the same increase trend presented during spring, summer, autumn and winter with 2013 to be the year with maximum ASST observed values. Innovative aspects comprise of straightforward integration and modeling of available tools, providing a versatile platform of analysis and semi-automation of the operation. In addition, the fine resolution maps that extracted from the analysis with a wide spatial coverage, allows the detail representation of SST and ASST respectively in the region.

Satellite observations and an ecosystem model are used to understand the variability in the planktonic ecosystem off Peru for the period January 1996 to May 1998. The objective of this study is to quantify the changes in the ecosystem components, carbon pathways, and available food for small pelagic fish that occur associated with the change in physical forcing due to El Nino. Two periods are distinguished based on the observed sea level anomaly: a La Nina (LaN) period (1996) in which sea level was below normal and El Nino (EN), the average conditions for December 1997, in which the sea level was anomalously high. There are three phytoplankton size classes (pico-, nano-, and net-phytoplankton) which compete for nutrients and are eaten by three zooplankton size classes. The ecosystem model is forced by alongshore wind speed measured by the NASA Scatterometer (NSCAT) and the European Remote-sensing Satellites (ERS-1 and ERS-2). Larger, slower growing organisms are more sensitive to physical disturbance than smaller organisms (Carr, 1998]. In the present simulation as well, the primary effect of the El Nino (reduced nutrient supply, and increased temperature) is to reduce the biomass of large cells (netphytoplankton) and consequently of the zooplankton that rely on large cells as food source. EN conditions are accompanied by a rearrangement of carbon pathways: comparable uptake goes into reduced biomass accumulation, increased losses to respiration, reduced carbon export, and much reduced carbon available to fish. The star indicates the remotely sensed biomass (assuming a constant carbon to chlorophyll ratio of 60) as measured by the Ocean Color and Temperature Sensor (Nov.-Dec. 1996) and the Sea-viewing Wide Field-of-view Sensor (Dec. 1997). The model, which assumes no light limitation, overestimates total phytoplankton biomass. Additional Information is contained in the original.

Statistical analyses of monthly mean sea surface temperatures (SST) from observations and from a hierarchy of global coupled ocean-atmosphere models were carried out with the focus on the midlatitudes (25 N-50 N). The spectra of the simulated SSTs have been tested against the null hypothesis of Hasselmann's stochastic climate model, which assumes an AR(1)-process for the SST variability in its simplest version. It was found that the spectra of the SST variability in the observations and in the CGCMs with fully dynamical ocean models differ significantly from AR(1)-processes, while the SST variability in an AGCM coupled to a slab ocean is consistent with an AR(1)-process. The deviations of the SST spectra from the fitted AR(1) spectra are not due to spectral peaks but are due to a slower increase of variance from seasonal to decadal time scales. Parts of these differences can be attributed to the interaction between the mixed layer and the sub-mixed-layer ocean. While the mixed layer depth variability generates SST variability on seasonal and shorter time scales, the heat exchange with the deep ocean, reduces variability on longer time scales. (orig.)

The nature of observed variations in temperature-salinity (T-S) relationship between El Nino and non-El Nino years in the pycnocline of the eastern equatorial Pacific Ocean (NINO3 region, 5(deg)S-5(deg)N, 150(deg)W-90(deg)W) is investigated using an ocean general circulation model. The origin of the subject water mass is identified using the adjoint of a simulated passive tracer. The higher salinity during El Nino is attributed to larger convergence of saltier water from the Southern Hemisphere and smaller convergence of fresher water from the Northern Hemisphere.

The veracity of modeled air-sea interactions in the Indian Ocean during the South Asian summer monsoon is examined. Representative simulations of the twentieth century climate, produced by coupled general circulation models as part of the Intergovernmental Panel on Climate Change Fourth Assessment Report, are the analysis targets along with observational data. The analysis shows the presence of large systematic biases in coupled simulations of boreal summer precipitation, evaporation, and sea surface temperature (SST) in the Indian Ocean, often exceeding 50% of the climatological values. Many of the biases are pervasive, being common to most simulations. The representation of air-sea interactions is also compromised. Coupled models tend to emphasize local forcing in the Indian Ocean as reflected by their large precipitation-SST correlations, at odds with the weak links in observations which suggest the importance of non-local controls. The evaporation-SST correlations are also differently represented, indicating atmospheric control on SST in some models and SST control on evaporation in others. The Indian monsoon rainfall-SST links are also misrepresented: the former is essentially uncorrelated with antecedent and contemporaneous Indian Ocean SSTs in nature, but not so in most of the simulations. Overall, coupled models are found deficient in portraying local and non-local air-sea interactions in the Indian Ocean during boreal summer. In our opinion, current models cannot provide durable insights on regional climate feedbacks nor credible projections of regional hydroclimate variability and change, should these involve ocean-atmosphere interactions in the Indian basin. (orig.)

Full Text Available Epidemics of lathyrism, a neurological syndrome of spastic paraparesis, have occurredduring severe droughts in Europe, Asia, and Africa for millenia. Causation is linked toexposure to β-N-oxalyl-L-α,β-diaminopropionic acid (β-L-ODAP, a neurotoxin in Lathyrussativus. Lathyrism shares neurological features with konzo, a syndrome of predominantlyspastic paraparesis which occurs during droughts in East and Central Africa and is linked to El Nino activity. This study was done to determine the relationship of lathyrism epidemics to phases of El Nino-southern oscillation (ENSO and Pacific decadal oscillation (PDO, and to propose a model to explain why the geospatial distributions of lathyrism and konzo are non-overlapping. Contingency table of phases of ENSO and occurrence of lathyrism epidemics in Central Provinces, India from 1833–1902 was created and odds ratio was calculated. Wavelet spectra of time series of annual occurrence of lathyrism in Rewah district, India, and its coherence with ENSO and PDO from 1894–1920 were performed. Lathyrism epidemic was associated with El Nino phase of ENSO, odds ratio 378 (95 % 32–4475. Global spectra showed peaks at periodicity of 2.5 and 4.6 years for lathyrism; 2.7 and 5.0 years for PDO; and 2.5, 4.6, 7.0 years for ENSO. Spectrograms showed time-varying periodicities of 2.5–3.5 and 4.5–5.5 years for lathyrism; 2.0–3.0 and 6.5–9.0 years for ENSO; and 3.5 and 5.0 years for PDO, p < 0.0001. Spectral coherence were at 2.0–3.5 and 4.5–5.0 years for ENSO and lathyrism p < 0.0001, and 5.0 years for PDO and lathyrism p < 0.05. The droughts of El Ninos initiate dependence on Lathyrus sativus, which exposes the population to neurotoxic β-L-ODAP. Public health control of lathyrism epidemics should include development of models to forecast El Ninos and initiate food programmes in susceptible areas.

The space-time features of major vorticity disturbances over the western North Pacific during the 1997-98 El Ni(n)o ranked as one of the strongest events on record was investigated in this study. We distinguished the different roles that these disturbances had on different timescales in causing the reversal or turnabout of the El Ni(n)o event. Remarkable differences in the various disturbances of synoptic, intraseasonal, and interannual timescales were found in the time evolution, propagation, and in their contributions to the changes in nearequatorial zonal flow, which was crucial to the demise of the warm sea surface temperature anomalies in the central-eastern Pacific. It is hypothesized that the westward-traveling synoptic and intraseasonal oscillations in the western North Pacific might be considered as a self-provided negative feedback from the El Ni(n)o and played an additional role in its reversal in comparison with other interannual internal and external forcings.In this case, the off-equatorial synoptic and intraseaonal fluctuations served as a stochastic forcing for the tropical ocean and gave rise to the aperiodicity or irregularity of the El Ni(n)o-Southern Oscillation.

This study examines the mechanisms governing the teleconnections associated with the long-lived La Niña variability in the tropical Indian Ocean (TIO) sea surface temperature (SST) anomalies using observational and reanalysis products. Two long-lived La Niña events (1973 to 1976 and 1998 to 2001) are observed in the recent years, one falling before and the other after the mid 1970's climatic shift. The winter (boreal) and spring (November to April) TIO SST is highly influenced by long-lived La Niña forcing. Climatic shift in mid 1970s contributes to the changes in TIO SST pattern during these two long-lived La Niña events. Surface heat flux variations due to long-lived La Niña contribute to the SST changes except in the southwest TIO. The upwelling favorable local surface wind stress curl and upwelling Rossby waves originating from the east are the dominant mechanisms responsible for the La Niña related winter time SST cooling over the southwest TIO. Long-lived La Niña induced surface wind anomalies enhance the fall Wyrtki Jet in the equatorial Indian Ocean resulting large scale anomalous heat transport. Local SST cooling reduces convection and contributes to the low rainfall over southwest TIO and the northern parts of Madagascar Island.

Cryogenic heat load analysis is an important aspect for stable operation of Tokamaks employing large scale superconducting magnets. Steady State Superconducting Tokamak (SST-1) at IPR is equipped with superconducting magnets system (SCMS) comprising sixteen numbers of modified ‘D’ shaped toroidal field (TF) and nine poloidal field (PF) superconducting coils which are wound using NbTi/Cu based cable-in conduit conductor (CICC). SST-1 magnets operation has flexibility to cool either in two-phase with sub-cooling, two-phase without sub-cooling or single phase (supercritical) helium using a dedicated 1.3 kW helium refrigerator cum liquefier (HRL). Here, we report gross heat losses for integrated TF superconducting magnets of SST-1 during the plasma campaign using cryogenic helium supply/return thermodynamic data from cryoplant. Heat loads mainly comprising of steady state as well as transient loads are smoothly absorbed by SST-1 cryogenic helium plant during plasma experiments. The corresponding heat produced in the coils is totally released to the helium flowing through the TF coils, which in turn is dumped into liquid helium stored in main control Dewar. These results are very useful reference for heat loss analysis for TF as well as PF coils and provides database for future operation of SST-1 machine.

We present evidence suggesting that the late 1960's Sahel drought was linked to an abrupt cooling in the extratropical North Atlantic, whose influence was then propagated to the Sahel by atmospheric teleconnection. Such linkages have been observed in paleoclimate during abrupt climate changes of the last glacial period. They have also occurred in coupled model simulations of Atlantic meridional overturning circulation (AMOC) slowdown, the latter being the leading cause of said paleoclimate abrupt changes. The AMOC-slowdown simulations show a characteristic global pattern of climate changes, including a northern hemispheric-wide cooling and increased surface pressure, and weakening of the West African and Asian monsoons. We show that an observed northern-hemispheric pattern of changes, resembling the AMOC slowdown, occurred during the late 1960's, co-incident with the Sahel drought. A combined principal component analysis of 20th century surface temperature, sea level pressure and precipitation extracts a leading mode whose spatial pattern closely resemble the impacts of AMOC slowdown. A similar analysis of AMIP-type simulations forced by 20th century observed forcings shows a similar result, suggesting that the origins of the climate change reside in SST changes, in particular over extratropical North Atlantic. Taken together, the results suggests the influence of extratropical North Atlantic cooling on the 20th century Sahel drought, and a teleconnection pathway through surface/tropospheric cooling. Motivated by our observational result, we investigated atmospheric teleconnection mechanisms of extratropical North Atlantic cooling in an atmospheric general circulation model (GCM) coupled with slab ocean. Our results indicate the central role of tropospheric cooling in communicating the influence on the Sahel. We explicitly show this using regional climate model simulation of the Sahel, with air temperature and associated humidity anomalies from the GCM simulation

The global effects of the 2004 El Nino on tropospheric ozone and H2O based on Aura OM1 and MLS measurements are analyzed. Although it was a weak El Nino from a historical perspective, it produced significant changes in these parameters in tropical latitudes. Tropospheric ozone increased by 10-20% over most of the western Pacific region and decreased by about the same amount over the eastern Pacific region. H2O in the upper troposphere showed similar changes but with opposite sign. These zonal changes in tropospheric ozone and H2O are caused by the eastward shift in the Walker circulation in the tropical pacific region during El Nino. For the 2004 El Nino, biomass burning did not have a significant effect on the ozone budget in the troposphere unlike the 1997 El Nino. Zonally averaged tropospheric column ozone did not change significantly either globally or over the tropical and subtropical latitudes.

利用中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室发展的气候海洋模式(LICOM),考察了两种热通量边界条件(牛顿冷却型边界条件和总体公式型边界条件)对热带太平洋海温平均态和年际变率模拟效果的影响.结果显示,在两种边界条件下,模式均能较好的再现海温的年平均空间分布特征和季节循环特征.对比分析发现,在牛顿冷却条件下,模拟结果与观测更加接近,这是因为该条件会通过调整净海表热通量使模拟海温向观测的气候态海温逼近.就年际变率而言,牛顿冷却条件下模式模拟的净海表热通量负反馈作用偏强,从而使ENSO模拟偏弱,进而使中东太平洋的异常经向温度平流模拟偏弱,造成海温异常的经向尺度偏窄.负反馈的强度与耦合系数的选取有关.而总体公式条件下模式能够合理地模拟出ENSO相关的热通量负反馈过程,从而能正确的模拟出ENSO振幅以及ENSO空间型.因此,当利用海洋模式对气候平均态海温进行模拟时,两种条件均可采用,但以牛顿冷却条件为佳；而当对海温的年际变率进行模拟时,应该采用总体公式型边界条件.%Both Newton cooling scheme (I. E. Prescribed total heat fluxes added with a relaxation term) and bulk formula parameterization scheme are widely used in offline Ocean General Circulation model simulations. These two thermal forcing schemes are compared here in two simulations using LASG/IAP climate ocean model (named LICOM) in terms of the performance over tropical Pacific Ocean. The results indicate that for both the annual mean SST distribution and the annual cycle of SST over tropical pacific, the two schemes show reasonable performance, although the Newton cooling scheme shows even less bias due to its relaxation to observed climatological SST. The El Nino amplitude in the Newton cooling scheme simulation is weaker than that in

A simple approach that considers both internal decadal variability and the effect of anthropogenic forcing is developed to predict the decadal components of global sea surface temperatures (SSTs) for the three decades 2011–2040. The internal decadal component is derived by harmonic wave expansion analyses based on the quasiperiodic evolution of the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO), as obtained from observational SST datasets. Furthermore, the external decadal component induced by anthropogenic forcing is assessed with a second-order fit based on the ensemble of projected SSTs in the experiments with multiple coupled climate models associated with the third Coupled Model Intercomparison Project (CMIP3) under the Intergovernmental Panels on Climate Change (IPCC) Special Reports on Emissions Scenario (SRES) A1B. A validation for the years from 2002 to 2010 based on a comparison of the predicted and the observed SST and their spatial correlation, as well as the root mean square error (RMSE), suggests that the approach is reasonable overall. In addition, the predicted results over the 50°S-50°N global band, the Indian Ocean, the western Pacific Ocean, the tropical eastern Pacific Ocean, and the North and the South Atlantic Ocean are presented.

Full Text Available state-of-the-art coupled ocean-atmosphere model’s Niño3.4 SST forecast for January 2016 is presented, followed by an evaluation of the model’s ability to have predicted events of similar magnitude in the past. The January forecast, initialized in July...

This report quantified potential hydrogen diffusion through Hanford Site Single-Shell tank (SST) domes if the SSTs were hypothetically sealed airtight. Results showed that diffusion would keep headspace flammable gas concentrations below the lower flammability limit in the 241-AX and 241-SX SST. The purpose of this document is to quantify the amount of hydrogen that could diffuse through the domes of the SSTs if they were hypothetically sealed airtight. Diffusion is assumed to be the only mechanism available to reduce flammable gas concentrations. The scope of this report is limited to the 149 SSTs.

and quantify regional diurnal warming from the experimental MSG/SEVIRI hourly SST fields, for the period 2006-2012. ii) To investigate the impact of the increased SST temporal resolution in the atmospheric model WRF, in terms of modeled 10-m winds and surface heat fluxes. Withing this context, 3 main tasks...... regional diurnal warming over the SEVIRI disk, a SEVIRI derived reference field representative of the well mixed night-time conditions is required. Different methodologies are tested and the results are validated against SEVIRI pre-dawn SSTs and in situ data from moored and drifting buoys....

ASTRI is a Flagship Project financed by the Italian Ministry of Education, University and Research, and led by INAF, the Italian National Institute of Astrophysics. The primary goal of the ASTRI project is the realization of an end-to-end prototype of a Small Size Telescope for the Cherenkov Telescope Array. The prototype, named ASTRI SST-2M, is based on a completely new double mirror optics design and will be equipped with a camera made of a matrix of SiPM detectors. Here we describe the ASTRI SST-2M camera concept: basic idea, detectors, electronics, current status and some results coming from experiments in lab.

Full Text Available This study used the Community Atmospheric Model 3.5 (CAM3.5 to investigate the effects of carbonaceous aerosols on climate. The simulations include control runs with 3 times the mass of carbonaceous aerosols as compared to the model's default carbonaceous aerosol mass, as well as no-carbon runs in which carbonaceous aerosols were removed. The slab ocean model (SOM and the fixed sea surface temperature (SST were used to examine effects of ocean boundary conditions. Throughout this study, climate response induced by aerosol forcing was mainly analyzed in the following three terms: (1 aerosol radiative effects under fixed SST, (2 effects of aerosol-induced SST feedbacks, and (3 total effects including effects of aerosol forcing and SST feedbacks. The change of SST induced by aerosols has large impacts on distribution of climate response; the magnitudes in response patterns such as temperature, precipitation, zonal winds, mean meridional circulation, radiative fluxes, and cloud coverage are different between the SOM and fixed SST runs. Moreover, different spatial responses between the SOM and fixed SST runs can also be seen in some local areas. This implies the importance of SST feedbacks on simulated climate response. The aerosol dimming effects cause a cooling predicted at low layers near the surface in most carbonaceous aerosol source regions. The temperature response shows a warming (cooling predicted in the north (south high latitudes, suggesting that aerosol forcing can cause climate change in regions far away from its origins. Our simulation results show that direct and semidirect radiative forcing due to carbonaceous aerosols decreases rainfall in the tropics. This implies that carbonaceous aerosols have possibly strong influence on weakening of the tropical circulation. Most changes in precipitation are negatively correlated with changes of radiative fluxes at the top of model. The changes in radiative fluxes at top of model are physically

The work presented here is directed toward assessment of environmental effects of the supersonic transport (SST). The model used for the purpose includes vertical eddy transport and the photochemistry of the O-H-N system. It is found that the flight altitude has a pronounced effect on ozone depletion. The largest ozone reduction occurs for NO deposition above an altitude of 20 km.

The westward propagation of sea surface temperature (SST) anomalies is one of the main characteristics of one of the theories of the Atlantic Multidecadal Oscillation. Here we use techniques from complex network modeling to investigate the existence of the westward propagation in the North Atlantic

Conclusion:The relatively low sensitivity of the SST observed in this study calls for its ... Slides were examined under royal blue. LED (455nm) excitation filter at X10 eye piece and X20 ... using a light microscope (Olympus CH) for presence.

Aerosol emission by the anthropogenic source has increased in the 20th century and the effects on climate have received much attention for understanding of historical climate change and variability. Aerosols contribute to change solar radiation at the surface directly and indirectly enhance radiative effect through cloud properties changes, altering surface climate and large-scale atmospheric circulation as well. Recently Oldenborgh et al. [2012] , Chikamoto et al. [2012] and Wang et al.[2012] showed the Pacific decadal scale variability is able to be affected by the aerosols. Since climate response in global warming is modulated by decadal variability and the Asian monsoon circulation changes are known to be affected by anthropogenic aerosols [Lau et al., 2006; Ramana et al., 2010], aerosol impact over the Pacific needs to be studied. Both effects by natural and anthropogenic emissions are important. To simulate the North Atlantic climate variability, aerosol forcing is important [Mann and Emanuel, 2006; Oldenborgh et al., 2012]. In particular, it is known to be better represented when indirect effect by anthropogenic emitted aerosols is considered [Booth et al, 2011]. Therefore, considering previous studies, this study investigates aerosol effect with indirect effect by anthropogenic aerosol emission over the Pacific. In this study, comparison between historical run and fixed aerosol experiments using HadGEM2-AO shows that multidecadal variability in historical run is closer to the observed ERSST variability over the North Pacific. In detrended SST anomalies, warming and cooling in the period of 1925-1960 and 1965-1990 are reproduced in aerosol forced historical simulation. The climate variability is partly related by the shortwave changes in response to aerosols emission. There is cooling effect, directly. Here, we are interested in indirect cloud property changes and the Pacific SST variability is investigated using previous results [Williams et al., 2001

We construct directed and weighted climate networks based on near surface air temperature to investigate the global impacts of El Nino and La Nina. We find that regions which are characterized by higher positive or negative network in weighted links, are exhibiting stronger correlations with the El Nino basin and are warmer or cooler during El Nino or La Nina periods. These stronger in-weighted activities are found to be concentrated in localized areas, as compared to non-El Nino periods, whereas a large fraction of the globe is not influenced by the events. The regions of localized activity vary from one El Nino (La Nina) event to another; still some El Nino (La Nina) events are more similar to each other. We quantify this similarity using network community structure. The results and methodology reported here may be used to improve the understanding and prediction of El Nino or La Nina events and also may be applied in the investigation of other climate variables.

Full Text Available This study used Community Atmospheric Model 3.5 (CAM3.5 to investigate the effects of carbonaceous aerosols on climate. The simulations include control runs with carbonaceous aerosols and no carbon runs in which carbonaceous aerosols were removed. The Slab Ocean Model (SOM and the fixed Sea Surface Temperature (SST were used to examine effects of ocean boundary conditions. Throughout this study, climate response induced by aerosol forcing was mainly analyzed in the following three terms: (1 aerosol radiative effects under fixed SST, (2 effects of aerosol-induced SST feedbacks , and (3 total effects including effects of aerosol forcing and SST feedbacks. The change of SST induced by aerosols has large impacts on distribution of climate response, the magnitudes in response patterns such as temperature, precipitation, zonal winds, mean meridional circulation, radiative fluxes and cloud coverage are different between the SOM and fixed SST runs. Moreover, different spatial responses between the SOM and fixed SST runs can also be seen in some local areas. This implies the importance of SST feedbacks on simulated climate response. The aerosol dimming effects cause a cooling predicted at low layers near the surface in most of carbonaceous aerosol source regions. The temperature response shows a warming (cooling predicted in the north (south high latitudes, suggesting that aerosol forcing can cause climate change in regions far away from its origins. Our simulation results show that warming of the troposphere due to black carbon decreases rainfall in the tropics. This implies that black carbon has possibly strong influence on weakening of the tropical circulation. Most of these changes in precipitation are negatively correlated with changes of radiative fluxes at the top of model. The changes in radiative fluxes at top of model are physically consistent with the response patterns in cloud fields. On global average, low-level cloud coverage increases, mid

The 1997/98 is a strong El Nino warm event, while the 1998/99 is a moderate La Nina cold event. We have investigated surface heat budgets and sea surface temperature (SST) tendency for these two events in the tropical western Pacific and eastern Indian Oceans using satellite-retrieved surface radiative and turbulent fluxes. The radiative fluxes are taken from the Goddard Satellite-retrieved Surface Radiation Budget (GSSRB), derived from radiance measurements of the Japanese Geostationary Meteorological Satellite 5. The GSSRB covers the domain 40 deg S - 4 deg N, 90 deg E-17 deg W and a period from October 1997 to December 2000. The spatial resolution is 0.5 deg x 0.5 deg lat-long and the temporal resolution is 1 day. The turbulent fluxes are taken from Version 2 of the Goddard Satellite-based Surface Turbulent Fluxes (GSSTF-2). The GSSTF-2 has a spatial resolution of 1 deg x 1 deg lat-long over global Oceans and a temporal resolution of 1 day covering the period July 1987-December 2000. Daily turbulent fluxes are derived from the S S M (Special Sensor Microwave/Imager) surface wind and surface air humidity, and the SST and 2-m air temperature of the NCEP/NCAR reanalysis, using a stability-dependent bulk flux algorithm. The changes of surface heat budgets, SST and tendency, cloudiness, wind speed, and zonal wind stress of the 1997/98 El Nino relative to the1998/99 La Nina for the northern winter and spring seasons are analyzed. The relative changes of surface heat budgets and SST tendency of the two events are quite different between the tropical eastern Indian and western Pacific Oceans. For the tropical western Pacific, reduced solar heating (more clouds) is generally associated with decreased evaporative cooling (weaker winds), and vise versa. The changes in evaporative cooling over-compensate that of solar heating and dominate the spatial variability of the changes in net surface heating. Both solar heating and evaporative cooling offset each other to reduce

Full Text Available In response to its users’ needs, the National Oceanic and Atmospheric Administration (NOAA initiated reanalysis (RAN of the Advanced Very High Resolution Radiometer (AVHRR Global Area Coverage (GAC; 4 km sea surface temperature (SST data employing its Advanced Clear Sky Processor for Oceans (ACSPO retrieval system. Initially, AVHRR/3 data from five NOAA and two Metop satellites from 2002 to 2015 have been reprocessed. The derived SSTs have been matched up with two reference SSTs—the quality controlled in situ SSTs from the NOAA in situ Quality Monitor (iQuam and the Canadian Meteorological Centre (CMC L4 SST analysis—and analyzed in the NOAA SST Quality Monitor (SQUAM online system. The corresponding clear-sky ocean brightness temperatures (BT in AVHRR bands 3b, 4 and 5 (centered at 3.7, 11, and 12 µm, respectively have been compared with the Community Radiative Transfer Model simulations in another NOAA online system, Monitoring of Infrared Clear-sky Radiances over Ocean for SST (MICROS. For some AVHRRs, the time series of “AVHRR minus reference” SSTs and “observed minus model” BTs are unstable and inconsistent, with artifacts in the SSTs and BTs strongly correlated. In the official “Reanalysis version 1” (RAN1, data from only five platforms—two midmorning (NOAA-17 and Metop-A and three afternoon (NOAA-16, -18 and -19—were included during the most stable periods of their operations. The stability of the SST time series was further improved using variable regression SST coefficients, similarly to how it was done in the NOAA/NASA Pathfinder version 5.2 (PFV5.2 dataset. For data assimilation applications, especially those blending satellite and in situ SSTs, we recommend bias-correcting the RAN1 SSTs using the newly developed sensor-specific error statistics (SSES, which are reported in the product files. Relative performance of RAN1 and PFV5.2 SSTs is discussed. Work is underway to improve the calibration of AVHRR/3s and

Climate variability associated with the West African monsoon (WAM) has important environmental and socio-economic impacts in the region. However, state-of-the-art climate models still struggle in producing reliable climate predictions. An important cause of this low predictive skill is the sensitivity of climate models to different forcings. In this study, the mechanisms linking the WAM dynamics to the CO2 forcing are investigated, by comparing the effect of the CO2 direct radiative effect with its indirect effect mediated by the global sea surface warming. The July-to-September WAM variability is studied in climate simulations extracted from the Coupled Model Intercomparison Project Phase 5 archive, driven by prescribed sea surface temperature (SST). The individual roles of global SST warming and CO2 atmospheric concentration increase are investigated through idealized experiments simulating a 4 K warmer SST and a quadrupled CO2 concentration, respectively. Results show opposite and competing responses in the WAM dynamics and precipitation. A dry response (-0.6 mm/day) to the SST warming is simulated in the Sahel, with dryer conditions over western Sahel (-0.8 mm/day). Conversely, the CO2 increase produces wet conditions (+0.5 mm/day) in the Sahel, with the strongest response over central-eastern Sahel (+0.7 mm/day). The associated responses in the atmospheric dynamics are also analysed, showing that the SST warming affects the Sahelian precipitation through modifications in the global tropical atmospheric dynamics, reducing the importance of the regional drivers, while the CO2 increase reinforces the coupling between precipitation and regional dynamics. A general agreement in model responses demonstrates the robustness of the identified mechanisms linking the WAM dynamics to the CO2 direct and indirect forcing, and indicates that these primary mechanisms are captured by climate models. Results also suggest that the spread in future projections may be caused by

Climate variability associated with the West African monsoon (WAM) has important environmental and socio-economic impacts in the region. However, state-of-the-art climate models still struggle in producing reliable climate predictions. An important cause of this low predictive skill is the sensitivity of climate models to different forcings. In this study, the mechanisms linking the WAM dynamics to the CO2 forcing are investigated, by comparing the effect of the CO2 direct radiative effect with its indirect effect mediated by the global sea surface warming. The July-to-September WAM variability is studied in climate simulations extracted from the Coupled Model Intercomparison Project Phase 5 archive, driven by prescribed sea surface temperature (SST). The individual roles of global SST warming and CO2 atmospheric concentration increase are investigated through idealized experiments simulating a 4 K warmer SST and a quadrupled CO2 concentration, respectively. Results show opposite and competing responses in the WAM dynamics and precipitation. A dry response (-0.6 mm/day) to the SST warming is simulated in the Sahel, with dryer conditions over western Sahel (-0.8 mm/day). Conversely, the CO2 increase produces wet conditions (+0.5 mm/day) in the Sahel, with the strongest response over central-eastern Sahel (+0.7 mm/day). The associated responses in the atmospheric dynamics are also analysed, showing that the SST warming affects the Sahelian precipitation through modifications in the global tropical atmospheric dynamics, reducing the importance of the regional drivers, while the CO2 increase reinforces the coupling between precipitation and regional dynamics. A general agreement in model responses demonstrates the robustness of the identified mechanisms linking the WAM dynamics to the CO2 direct and indirect forcing, and indicates that these primary mechanisms are captured by climate models. Results also suggest that the spread in future projections may be caused by

Spatial correlations in the annual rainfall anomalies are analyzed using principal component analysis (PCA). Cross correlation analysis and composites are used to measure the influence of sea-surface temperature anomalies (SSTAs) in the tropical Atlantic (TA) and the tropical Pacific Ocean on the seasonal rainfall in Suriname. It is shown that the spatial and time variability in rainfall is mainly determined by the meridional movement of the inter-tropical convergence zone (ITCZ). The rainfall anomalies are fairly uniform over the whole country. The strongest correlation in the December-January rainfall (short wet season) at station Cultuurtuin is found to occur with the SSTAs in the Pacific region and is about ckNino1 + 2 = 0.59 at lag 1 month. In the March-May rainfall (beginning of the long wet season), there is a lagged correlation with the SSTAs in the Pacific region (clag3Nino1 + 2 = 0.59). The June-August rainfall (end of the long wet season) shows the highest correlation with SSTAs in the TSA region and is about c = -0.52 for lag 0. In the September-November long dry season there is also a lagged correlation with the TSA SSTAs of about clag3 = 0.66. These different correlations and predictors can be used for seasonal rainfall predictions.

By making full use of GMS TBB data, diagnosis and analysis of the formation and development of El Ni(n)o event in 2002 and 2003 were made. It suggests that the first clue of the El Ni(n)o event appeared in December 2001. The event was formed at the end of 2002 after five phases of development, and came into the phase of flourishing in the winter of 2002. From the analysis the dynamics, it is noted that that the position of the ascending branch of Walker cell was moving from the equatorial west Pacific to the equatorial central Pacific in the phase of formation and development of the El Ni(n)o event. The process of diagnosis shows that it can provide an important clue for forecasting the genesis and development of the El Ni(n)o episodes.

Targeted experiments with a comprehensive chemistry-climate model are used to demonstrate that seasonality and the location of the peak warming of sea surface temperatures dictate the response of stratospheric water vapor to El Nino. In spring, El Nino events in which sea surface temperature anomalies peak in the eastern Pacific lead to a warming at the tropopause above the warm pool region, and subsequently to more stratospheric water vapor (consistent with previous work). However, in fall and in early winter, and also during El Nino events in which the sea surface temperature anomaly is found mainly in the central Pacific, the response is qualitatively different: temperature changes in the warm pool region are nonuniform and less water vapor enters the stratosphere. The difference in water vapor in the lower stratosphere between the two variants of El Nino approaches 0.3 ppmv, while the difference between the winter and spring responses exceeds 0.5 ppmv.

A class of nonlinear coupled system for E1 Nino-Southern Oscillation (ENSO) model is considered. Using the asymptotic theory and method of variational iteration, the asymptotic expansion of the solution for ENSO models is obtained.

Models of global climate phenomena of low to intermediate complexity are very useful for providing an understanding at a conceptual level. An important aspect of such models is the presence of a number of feedback loops that feature considerable delay times, usually due to the time it takes to transport energy (for example, in the form of hot/cold air or water) around the globe. In this paper we demonstrate how one can performed a bifurcation analysis of the behaviour of a periodically forced delay differential equation (DDE) in dependence on key parameters. As a concrete example we consider the El-Nino Southern Oscillation (ENSO), which is a sea surface temperature oscillation on a multi-year scale in the basin of the Pacific Ocean. One can think of ENSO as being generated by an interplay between two feedback effects, one positive and one negative, which act only after some delay that is determined by the speed of transport of sea-surface temperature anomalies across the Pacific. We perform here a case study...

An adaptive variational data assimilation method is proposed by Zhu and Kamachi[1]. This method can adaptively adjust the model state without knowing explicitly the model error covariance matrix. The method enables very flexible ways to form some reduced order problems. A proper reduced order problem not only reduces computational burden but also leads to corrections that are more consistent with the model dynamics that trends to produce better forecast. These features make the adaptive variational method a good candidate for SST data assimilation because the model error of an ocean model is usually difficult to estimate. We applied this method to an SST data assimilation problem using the LOTUS data sets and an ocean mixed layer model (Mellor-Yamada level 2.5). Results of assimilation experiments showed good skill of improvement subsurface temperatures by assimilating surface observation alone.

Climatic variability, related both to precipitation and river discharge, has been associated to ocean variability. Authors commonly relate Pacific sea surface temperature (SST) variation to South America (SA) precipitation. Zonal displacement of Walker cell, with intensified subsidence over northern portion of SA, Subtropical Jet strengthening/weakening over extratropical latitudes of SA are, respectively, dynamical reasons scientifically accepted for increasing and depletion of precipitation at the respective areas. Many studies point out the influence of tropical Atlantic SST anomalies in relation to precipitation/river discharge variability over northeast of Brazil. Aliseos variability at tropical Atlantic is also a physic process that contributes to explain precipitation and river flow variability over SA, mainly over the north portion. In this study, we aim to investigate the temporal correlation between SST, mainly from Pacific and Atlantic oceans, and rivers discharge at the Amazon region. Ji-Parana, Madeira and Tapajós river discharge in monthly and annual scale, between 1968 and 2008, were the time series selected to reach the purpose. Time series for river discharge were obtained from Agência Nacional de Águas (ANA, in Portuguese) and, SST data were obtained from CDC/NOAA. Before linear correlation computations between river discharge and SST have been made, seasonal cycle and linear tendency were removed from all original time series. Areas better correlated to river discharge at Amazon region show oceanic patterns apparently associated to PDO (Pacific Decadal Oscillation) and ENSO (El Niño-South Oscillation) variability, with absolute values greater than 0.3 and reaching 0.5 or 0.6. The spatial pattern observed at Pacific basin is similar to that showed by the first mode of PCA (Principal Component Analysis), such seen in many studies (the "horse shoe" pattern). In general, negative correlation values appear far more to the west of Pacific basin

For long duration steady state operation of SST1, it would be very crucial to maintain the plasma radial and vertical positions accurately. For designing the position controller in SST1 we have adopted the simple linear RZIP control model. While the vertical position instability is slowed down by a set of passive stabilizers placed closed to the plasma edge, a pair of in-vessel active feedback coils can adequately control vertical position perturbations of up to 1 cm. The shifts in radial position arising due to minor disruptions would be controlled by a separate pair of poloidal ﬁeld (PF) coils also placed inside the vessel, however the controller would ignore fast but insigniﬁcant changes in radius arising due to edge localised modes. The parameters of both vertical and radial position control coils and their power supplies are determined based on the RZIP simulations.

Before and during the El Niño of 2015-2016, regular and frequent application of climate monitoring and seasonal forecasts enabled early warning of food insecurity in Africa, Central America, and the Caribbean. As it happened, drought associated with the quasi-El Niño of 2014 had already adversely impacted harvests in Central America, Haiti, and Southern Africa, so the effects of the El Niño of 2015-2016 were especially hard-hitting and particularly devastating to crop conditions and food security. In the case of Ethiopia, 2014 conditions were normal but there were record rainfall deficits in 2015, with consequent crop failure, inadequate forage, and sharply curtailed water availability. Combining such agro-climatological information with knowledge of household economies, livelihood systems, markets & trade, and health & nutrition, FEWS NET constructed scenarios of food insecurity eight months into the future, with monthly updates. These scenarios informed assistance programming by USAID and partners. Overall, FEWS NET estimates that at least 18 million people will be severely food insecure during 2015/16 as a direct result of the impact of El Nino on rainfall. However, in Ethiopia, the contrast with the 1982-1983 El Niño is dramatic; though the two events were climatically similar, the human impacts of the 2015-2016 El Niño are much less, thanks not only to well-functioning early warning systems and large scale emergency response, but also improved social safety nets and lack of ongoing armed conflict. In southern Africa, El Nino resulted in extensive failed crops, with some areas of South Africa and Zimbabwe having insufficient rain to plant crops. Remote sensing products provided relevant information to depict the severity of rainfall and vegetation deficits. Likewise, in Central America and the Caribbean (Hispaniola), rainfall deficits were portrayed in the perspective of 30+ years of data.

In this paper, we will first introduce what is MIL-STD-1553B and why we choose it. Then we will analyze the characteristics and the reliability of this standard. When we use this protocol to implement our SDU system in the SST, we also need to describe the whole system in which the 1553 standard is used. Finally, we will put our most attention on the system design, including hardware interconnection and software program.

Recurring droughts in southwestern U.S. particularly California, have strained the existing water reserves of the region. Frequency, severity and duration of these recurring drought events may not be captured by the available instrumental records. Thus streamflow reconstruction becomes imperative to identify the historic hydroclimatic extremes of a region and assists in developing better water management strategies, vital for sustainability of water reserves. Tree ring chronologies (TRC) are conventionally used to reconstruct streamflows, since tree rings are representative of climatic information. Studies have shown that sea surface temperature (SST) and climate indices of southern oscillation index (SOI) and pacific decadal oscillation (PDO) influence U.S. streamflow volumes. The purpose of this study was to improve the traditional reconstruction methodology by incorporating the oceanic-atmospheric variables of PDO, SOI, and Pacific Ocean SST, alongwith TRC as predictors in a step-wise linear regression model. The methodology of singular value decomposition was used to identify teleconnected regions of streamflow and SST. The approach was tested on eleven gage stations in Sacramento River Basin (SRB) and San Joaquin River Basin (JRB). The reconstructions were successfully generated from 1800-1980, having an overlap period of 1932-1980. Improved results were exhibited when using the predictor variable of SST along with TRC (calibration r2=0.6-0.91) compared to when using TRC in combination with SOI and PDO (calibration r2=0.51-0.78) or when using TRC by itself (calibration r2=0.51-0.86). For future work, this approach can be replicated for other watersheds by using the oceanic-atmospheric climate variables influencing that region.

ASTRI is a Flagship Project financed by the Italian Ministry of Education, University and Research, and led by the Italian National Institute of Astrophysics, INAF. Primary goal of the ASTRI project is the design and production of an end-to-end prototype of Small Size Telescope for the CTA (Cherenkov Telescope Array) in a dual-mirror configuration (SST-2M) equipped with a camera at the focal plane composed by an array of Silicon Photo-Multipliers and devoted to the investigation of the highest gamma-ray energy band. The ASTRI SST-2M prototype will be placed at the INAF M.G. Fracastoro observing station in Serra La Nave on the Etna Mountain near Catania, Italy. After the verification tests, devoted to probe the technological solutions adopted, the ASTRI SST-2M prototype will perform scientific observations on the Crab Nebula and on some of the brightest TeV sources. Here we present the Serra La Nave site, its meteorological and weather conditions, the sky darkness and visibility, and the complex of auxiliary i...

As part of the Pathfinder program developed jointly by National Aeronautics and Space Administration (NASA) and National Oceanic and Atmospheric Administration (NOAA) a large database of in situ sea surface temperature (SST) measurements coincident with satellite data is now available to the user community. The Pathfinder Matchup Database (PMDB) is a multi-year, multi-satellite collection of coincident measurements from the Advanced Very High Resolution Radiometer (AVHRR) and broadly distributed buoy data (matchups). This database allows the user community to test and validate new SST algorithms to improve the present accuracy of surface temperature measurements from satellites. In this paper we investigate the performance of a global Pathfinder algorithm to specific regional conditions. It is shown that for zenith angles less than 45°, the best-expected statistical discrepancy between satellite and buoy data is about ∼0.5 K. In general, the bias of the residuals (satellite - buoy) is negative in most regions, except in the North Atlantic and adjacent seas, where the residuals are always positive. A seasonal signal in SST residuals is observed in all regions and is strongest in the Indian Ocean. The channel-difference term used as a proxy for atmospheric water vapor correction is observed to be unresponsive for columnar water vapor values greater than 45 mm and high zenith angles. This unresponsiveness of the channels leads to underestimation of sea surface temperature from satellites in these conditions.

The main features of SST interarmual and long-term variations in the Western Pacific Warm Pool area were studied by using regression analysis, running t-test and spectral analysis methods based on monthly mean SST data in the Pacific during 1950 - 1998. The results showed that the SST inter-annual and long-term variations in the Western Pacific Warm Pool area had evident regional features.There were significant differences in variation range, phase, period, occurrence time of abrupt variation between SST in the eastern area (east of 100°E) and SST in the western area (west of 100°E).

The first hint of the fact that solar eclipses mark the enhanced storms called El Nino or La Nina, came from the article by Robert Allan on analysis of frequencies of these events (2001, perhaps Fourier analysis). One mystery was the cause of a cycle with period 15 to 20 years. But the Saros Series of solar eclipses has a period of 18+ years. Then we had the data from Galapagos Islands for the whole 20th century (Philander 2004). The graph of high and low temperatures indicates El Ninos and La Ninas. A search through charts of solar eclipses for those with good locations for bringing high tides at the Tropics, gave a good picture: those at the eastern coast of the pacific Ocean gave El Ninos, and those at the west gave La Ninas. More than half of the peaks and troughs on the temperature graph can be identified with solar eclipses. We looked more closely at a few events that caused great storms. They are described in J. M. Nash's book, ``El Nino" (2002). The most striking case is that of the 1998 Feb. 22 solar eclipse, which corresponds to the so-called El Nino of 1997-98. In conclusion, I would say that the annual El nino effect is due to the sun's travel between the Tropic of Cancer and Tropic of Capricorn. But the enhanced El Niino/La Nina is due to the coming together of sun and moon in the solar eclipses, which seem to come irregularly.

Phase delays between two Nino indices-sea surface temperatures in Nino regions 1+2 and 3.4(1950-2001)-at different time scales are detected by wavelet analysis. Analysis results show that thereare two types of period bifurcations in the Nino indices and that period bifurcation points exist only in the region where the wavelet power is small. Interdecadal variation features of phase delays between the two indices vary with different time scales. In the periods of 40-72 months, the phase delay changes its sign in 1977: Nino 1+2 indices are 2-4 months earlier than Nino 3.4 indices before 1977, but 3-6 months later afterwards. In the periods of 20-40 months, however, the phase delay changes its sign in another way:Nino 1+2 indices are 1-4 months earlier before 1980 and during 1986-90, but 1-4 months later during 1980-83 and 1993-2001.

In this paper, the spreading way in the southern hemisphere that anomalous warm water piled in tropical eastern Pacific is analysed and then impact of El Nino on the variability of the Antarctic sea ice extent is investigated by using a dataset from 1970 to 2002. The analysis result show that in El Nino event the anomalous warm water piled in tropical eastern Pacific is poleward propagation yet the westward propagation along southern equator current hasn 't been discovered . The poleward propagation time of the anomalous warm water is about 1 year or so. El Nino event has a close relationship with the sea ice extent in the Amundsen sea , Bellingshausen sea and Antarctic peninsula. After El Nino appears , there is a lag of two years that the sea ice in the Amundsen sea , Bellingshausea sea, especially in the Antarctic peninsula decreases obviously. The processes that El Nino has influence with Antarctic sea ice extent is the warm water piled in tropical eastern Pacific poleward propagation along off the coast of southern America and cause the anomalous temperature raise in near pole and then lead the sea ice in Amundsen sea , Bellingshausen sea and Antarctic peninsula to decrease where the obvious decrease of the sea ice since 80 'decade has close relation to the frequently appearance of El Nino.

It is shown that, the wavelet regression detrended fluctuations of the monthly global temperature data (land and ocean combined) for the period 1880-2009yy, are completely dominated by one-third subharmonic resonance to annual forcing (both natural and anthropogenically induced). Role of the oceanic Rossby waves and the resonance contribution to the El Nino phenomenon have been discussed in detail.

This paper extends the work of our previous study, which showed the potential of using precipitation in the eastern Indian Ocean to predict when an El Nino would begin. The paper begins by showing the successful prediction of the 2002-03 El Nino. However, precipitation is really used as a substitute for wind (storms are usually accompanied by heavy wind), because a popular hypothesis is that winds (especially % winds out of the West) stir up the ocean surface in the western Pacific sending currents of warm waters to the east Pacific where El Ninos form. This paper shows that it is typical for storms that produce strong winds in the western Pacific to have traveled from the Indian Ocean. We begin in the Indian Ocean looking at strong bursts of wind over several days. The number of windy days seems to increase in the months prior to El Nino. We examined these relationships in detail for November 2001 to April 2002, before the recent El Nino, using NASA's TRMM and QuikSCAT data. We found in one case that a warming of the eastern Indian Ocean occurred about 25 days before heavy rainfall formed. As the stormed moved eastward it was followed (6 days later) by strong winds out of the West. The entire storm system (and warming of the sea) moved eastward through a small strip of water between Indonesia and Australia, before reaching the western Pacific. Thus, this paper increases our understanding of the physical processes leading to the formation of El Nino.

A statistical-stochastic model of the complete life cycle of North Atlantic (NA) tropical cyclones (TCs) is used to examine the relationship between climate and landfall rates along the North American Atlantic and Gulf Coasts. The model draws on archived data of TCs throughout the North Atlantic to estimate landfall rates at high geographic resolution as a function of the ENSO state and one of two different measures of sea surface temperature (SST): 1) SST averaged over the NA subtropics and the hurricane season and 2) this SST relative to the seasonal global subtropical mean SST (termed relSST). Here, the authors focus on SST by holding ENSO to a neutral state. Jackknife uncertainty tests are employed to test the significance of SST and relSST landfall relationships. There are more TC and major hurricane landfalls overall in warm years than cold, using either SST or relSST, primarily due to a basinwide increase in the number of storms. The signal along the coast, however, is complex. Some regions have large and significant sensitivity (e.g., an approximate doubling of annual major hurricane landfall probability on Texas from -2 to +2 standard deviations in relSST), while other regions have no significant sensitivity (e.g., the U.S. mid-Atlantic and Northeast coasts). This geographic structure is due to both shifts in the regions of primary TC genesis and shifts in TC propagation.

Full Text Available Apresenta-se, neste trabalho, uma análise estatística baseada em correlações entre as temperaturas globais da superfície do mar (TSM e as descargas do Rio Piancó, no sertão da Paraíba, principal contribuinte do reservatório de Coremas, na região. Os coeficientes globais de correlação foram obtidos entre as temperaturas médias da superfície do mar, para os trimestres de novembro a janeiro e de fevereiro a abril, e as descargas do Rio Piancó no reservatório de Coremas, para cada mês de fevereiro até maio, que compreendem a estação chuvosa na bacia hidrográfica do reservatório. Os resultados mostram correlações significativas entre as TSM das regiões NINO1+2 e NINO3 no Oceano Pacífico. Na área do Atlântico não existe um padrão de correlações bem definido.This paper presents a statistical analysis based on the correlation between the Global Sea Surface Temperatures (SST and the discharge of Piancó river the principal contributor to the Coremas reservoir in the Paraíba State. The global correlation coefficients were obtained between the mean Sea Surface Temperatures (SST for the November to January and February to April trimesters and the volume of water discharged by the Piancó river in the Coremas reservoir for each of the individual months from February to May, the rainy season in the region of the reservoir. The results show the existence of a strong negative correlation between the SST's of the Nino1+2 and Nino3 regions of the Pacific Ocean. For the Atlantic area no well defined pattern of correlation was found.

Highlights: • The paper gives overview on SST-1 data acquisition and central control system and future upgrade plans. • The lossless PXI based data acquisition of SST-1 is capable of acquiring around 130 channels with sampling frequency ranging from 10 KHz to 1 MHz sampling frequency. • Design, architecture and technologies used for central control system (CCS) of SST-1. • Functions performed by CCS. - Abstract: Steady State Superconducting Tokamak (SST-1) has been commissioned successfully and has been carrying out limiter assisted ohmic plasma experiments since the beginning of 2014 achieving a maximum plasma current of 75 kA at a central field of 1.5 T and the plasma duration ∼500 ms. In near future, SST-1 looks forward to carrying out elongated plasma experiments and stretching plasma pulses beyond 1 s. The data acquisition and central control system (CCS) for SST-1 are distributed, modular, hierarchical and scalable in nature The CCS has been indigenously designed, developed, implemented, tested and validated for the operation of SST-1. The CCS has been built using well proven technologies like Redhat Linux, vxWorks RTOS for deterministic control, FPGA based hardware implementation, Ethernet, fiber optics backbone for network, DSP for real-time computation & Reflective memory for high-speed data transfer etc. CCS in SST-1 controls & monitors various heterogeneous SST-1 subsystems dispersed in the same campus. The CCS consists of machine control system, basic plasma control system, GPS time synchronization system, storage area network (SAN) for centralize data storage, SST-1 networking system, real-time networks, SST-1 control room infrastructure and many other supportive systems. Machine Control System (MCS) is a multithreaded event driven system running on Linux based servers, where each thread of the software communicates to a unique subsystem for monitoring and control from SST-1 central control room through network programming. The CCS hardware

. Introduction [2] Bay of Bengal is known as one of locations of the most intensive deep convection and precipitation in the tropical oceans during the months of July and August, which are the two most active months of the Indian summer monsoon [Webster, 1995....0 [Pacanowski, 1996]. The model was run for the period 1982–98 with the following forcing: (1) FSU wind stress [Legler et al., 1989]; (2) NCEP/NCAR heat fluxes [Kalnay et al., 1996] with SST relaxed to monthly mean values of Reynolds and Smith [1994]; (3...

The frequent overexpression of the somatostatin receptors sst2 and sst5 in neuroendocrine tumors provides the molecular basis for therapeutic application of novel multireceptor somatostatin analogs. Although the phosphorylation of the carboxyl-terminal region of the sst2 receptor has been studied in detail, little is known about the agonist-induced regulation of the human sst5 receptor. Here, we have generated phosphosite-specific antibodies for the carboxyl-terminal threonines 333 (T333) and 347 (T347), which enabled us to selectively detect either the T333-phosphorylated or the T347-phosphorylated form of sst5. We show that agonist-mediated phosphorylation occurs at T333, whereas T347 is constitutively phosphorylated in the absence of agonist. We further demonstrate that the multireceptor somatostatin analog pasireotide and the sst5-selective ligand L-817,818 but not octreotide or KE108 were able to promote a detectable T333 phosphorylation. Interestingly, BIM-23268 was the only sst5 agonist that was able to stimulate T333 phosphorylation to the same extent as natural somatostatin. Agonist-induced T333 phosphorylation was dose-dependent and selectively mediated by G protein-coupled receptor kinase 2. Similar to that observed for the sst2 receptor, phosphorylation of sst5 occurred within seconds. However, unlike that seen for the sst2 receptor, dephosphorylation and recycling of sst5 were rapidly completed within minutes. We also identify protein phosphatase 1γ as G protein-coupled receptor phosphatase for the sst5 receptor. Together, we provide direct evidence for agonist-selective phosphorylation of carboxyl-terminal T333. In addition, we identify G protein-coupled receptor kinase 2-mediated phosphorylation and protein phosphatase 1γ-mediated dephosphorylation of T333 as key regulators of rapid internalization and recycling of the human sst5 receptor.

Full Text Available Nino Coni Santana National Park had been suffered by illegal logging, and other activities that are not environmenknowleage. Lack of a security and knowledgeabout forest also contributeto increasethe damage of Nino Coni Santana National Park (1The purpose of this research is to determine management strategy of Nino Coni National Park due to illegal logging in the area Tutuala and Mehara village at Tutuala sub-district,Lautem district, Timor Leste and determine management strategy of Nino Coni Santana National Park. Public perception obtained through questionnaires with purpose sampling method. The formula of management strategy for the damage in Nino Coni Santana National park use SWOT analysis to identify internal and external factors. The level of damage known by identifiy thearea due damaged by illegal logging.(2 The results showed that the damage by illegal logging at Nino Coni Santana national park caused because people are not involved in management of Nino Coni Santana National Park. The problems are illegal logging, encroachment,of forest, slash the wood harting wild animals, lack organization,andillegal grazing.(3 The management strategy of Nino Coni Santana National Park based on local culture, the establishment of a special UPTD that manage Coni Nino Santana forests, HKM and tourism programs, public development programs and cooperation of local people in order to utilize, surveillance and patrolling forests. In order to develop local knowledge as a base inNino Coni Santana National park,through HKM and tourism, Public socialization about the importance of forest. To measure the success of this management,should do monitoring, controlling andevaluation periodically by the government and involve the local people around Nino Cono Santana National Park.

El-Nino is the most important climate scale oscillation in the tropical atmosphere and earlier studies have shown that it impacts weather in different parts of the world. Since the long-term stability of wind resource is a primary requirement for the reliability of wind power generation, any modulation of the wind resource by the El-Nino constitutes valuable information for efficient harvesting of wind. In this study, we construct the global wind resource as described in Gunturu & Schlosser (2012) and use the method of composites to understand the impact of the El-Nino on the global wind resource. The results show that the impact of the El-Nino is to decrease the wind resource in the central United States, southern Australia and north central Africa. Further, interestingly, the wind resource increases in the Nordic sea and the continental areas around it. The Deccan plateau region of India also has reduced WPD due to the El-Nino as shown by the composites. On the other hand, the central US and southern Australia have increased WPD due to La-Nina and the resource decreases in India. The statistically significant results will be further discussed for their implications to the long term stability of the wind resource in the different regions of the world. We also substantiate the results with other suitable metrics.

This paper investigates possible warming effects of an El Ni(n)o event on the sea surface temperature anomaly(SSTA)in the northwestern Indian Ocean.Most pure positive Indian Ocean dipole(IOD)events (without an El Ni(n)o event co-occurring) have a maximum positive SSTA mainly in the central Indian Ocean south of the equator.while most co-occurrences with an El Ni(n)o event exhibit a northwest-southeast typical dipole mode.It is therefore inferred that warming in the northwestern Indian Ocean is closely related to the El Ni(n)o event.Based on the atmospheric bridge theory,warming in the northwestern Indian Ocean during co-occurring cases may be primarily caused by relatively less latent heat loss from the ocean due to reduced wind speed.The deepened thermocline also contributes to the warming along the east coast of Africa through the suppressed upwelling of the cold water.Therefore,the El Ni(n)o event is suggested to have a modulating effect on the structure of the dipole mode in the tropical Indian Ocean.

Full Text Available In this study, 169 lumbrinerids of the genera Ninoe and Cenogenus from the sublittoral zone of the Gulf of California and Gulf of Tehuantepec were analysed. Previous records in these regions of the Mexican Pacific included five species of Ninoe (N. chilensis, N. foliosa, N. gemmea, N. longibranchia and N. moorei and two of Cenogenus (originally identified as Ninoe fusca and N. fuscoides. Ninoe jessicae and N. marthae are newly described. They are characterized by the presence of multidentate hooded hooks from chaetiger 1 and at least 7 branchial filaments in the best developed branchiae. N. marthae n. sp. differs not only from N. jessicae n. sp. but also from the other species of the genus Ninoe, because only four teeth are present in maxilla II, while in all the other described species, 6-8 teeth are present there. The new species Cenogenus eliae is characterized by the presence of branchiae starting at chaetigers 32-51 and simple multidentate hooded hooks in all parapodia.

A class of El Nino atmospheric physics oscillation model is considered. The El Nino atmospheric physics oscillation is an abnormal phenomenon involved in the tropical Pacific ocean-atmosphere interactions. The conceptual oscillator model should consider the variations of both the eastern and westem Pacific anomaly patterns. An El Nino atmospheric physics model is proposed using a method for the variational iteration theory. Using the variational iteration method, the approximate expansions of the solution of corresponding problem are constructed. That is, firstly, introducing a set of functional and accounting their variationals, the Lagrange multiplicators are counted, and then the variational iteration is defined, finally, the approximate solution is obtained. From approximate expansions of the solution, the zonal sea surface temperature anomaly in the equatorial eastern Pacific and the thermocline depth anomaly of the seaair oscillation for El Nino atmospheric physics model can be analyzed. El Nino is a very complicated natural phenomenon. Hence basic models need to be reduced for the sea-air oscillator and are solved. The variational iteration is a simple and valid approximate method.

The response of the atmospheric circulation to greenhouse gas-induced SST warming is investigated using large ensemble experiments with two AGCMs, with a focus on the robust feature of the poleward shift of the eddy driven jet. In these experiments, large ensembles of simulations are conducted by abruptly switching the SSTforcing on from January 1st to focus on the wintertime circulation adjustment. A hybrid, nite amplitude wave activity budget analysis is performed to elucidate the nonlinear and irreversible aspects of the eddy-mean ow interaction during the adjustment of the zonal wind towards a poleward shifted state. The results conrm the results from earlier more idealized studies, particularly the importance of reduced dissipation of wave activity and the dominant role of the decrease of elective diffusivity in the midlatitudes. Some quantitative discrences do exist between the wave activity budgets of our more realistic experiments and the earlier idealized ones, including larger wave activity tendency and diabatic wave source, and a somewhat greater role of the changing PV gradient in the total reduction of the wave activity dissipation. The relative importance of wave breaking-induced PV mixing versus diabatic PV source in the evolution of the Lagrangian PV gradient is also investigated. The former plays the dominant role in the PV gradient formation during the initial phase of the jet shift, while the latter even opposes the evolution of the Lagrangian PV gradient at times. The possible involvement of the wave reflection level at the poleward flank of the mean jet is also investigated.

The rainfall variability for the state of Alagoas, Northeast of Brazil, was evaluated based on the Standardized Precipitation Index (SPI). Harmonic decomposition was applied to 31 years-long (1960-1990) series of SPI, from 33 stations, to relate their modes of variability to El Niño-Southern Oscillation (ENSO) and the Atlantic Ocean sea surface temperature (SST). The most important harmonics identified by the spectral analysis had periods of 10-15 and 2-3 years, followed by other oscillations with smaller periods. The 10-15 years harmonic was associated with the Atlantic interhemispheric SST gradient (AITG), a cross-equatorial dipole which impacts the northeast region of Brazil by influencing the position of the intertropical convergence zone (ITCZ), leading to dry or wet conditions. The 2-3 years harmonic was consistent with the variability of ENSO events. The harmonic analysis is a powerful tool to identify the principal modes of variability of SPI. Although the magnitude of SPI is underestimated in some cases, this tool significantly increases the knowledge of the main drivers of rainfall and droughts in the region.

First Wall Components (FWC) of SST-1 tokamak, which are in the immediate vicinity of plasma comprises of limiters, divertors, baffles, passive stabilizers are designed to operate long duration (1000 s) discharges of elongated plasma. All FWC consists of a copper alloy heat sink modules with SS cooling tubes brazed onto it, graphite tiles acting as armour material facing the plasma, and are mounted to the vacuum vessels with suitable Inconel support structures at ring & port locations. The FWC are very recently assembled and commissioned successfully inside the vacuum vessel of SST-1 undergoing a meticulous planning of assembly sequence, quality checks at every stage of the assembly process. This paper will present the metrology aspects & procedure of each FWC, both outside the vacuum vessel, and inside the vessel, assembly tolerances, tools, equipment and jig/fixtures, used at each stage of assembly, starting from location of support bases on vessel rings, fixing of copper modules on support structures, around 3800 graphite tile mounting on 136 copper modules with proper tightening torques, till final toroidal and poloidal geometry of the in-vessel components are obtained within acceptable limits, also ensuring electrical continuity of passive stabilizers to form a closed saddle loop, electrical isolation of passive stabilizers from vacuum vessel.

intertidal zone. We infer that forcing other than relative sea-level rise has altered the natural ability to support reef accretion on Hawaiian insular shelves. The limiting factor in these areas today is wave energy. Numbers of both large North Pacific swell events and hurricanes in Hawai'i are greater during El Nino years. We infer that if these major reef-limiting forces were suppressed, net accretion would occur in some areas in Hawai'i that are now wave-limited. Studies have shown that El Nino/Southern Oscillation (ENSO) was significantly weakened during early-mid Holocene time, only attaining an intensity similar to the current one ca. 5000 yr ago. We speculate that this shift in ENSO may assist in explaining patterns of Holocene Hawaiian reef accretion that are different from those of the present and apparently not related to relative sen-level rise.

pentads prior to MOK during La Nina, negative IOD, and concurrent La Nina and negative IOD years as compared to the El Nino, positive IOD, and concurrent El Nino and positive IOD years, indicating its significant role on MOK. The monsoon Hadley cell...

To study how the air and sea interact with each other during El Nino/La Nina onsets, extended associate pattern analysis (EAPA) is adopted with the simple ocean data assimilation (SODA) data. The results show that as El Nino/La Nina' s parents their behaviors are quite different, there does not exist a relatively independent tropical atmosphere but does exist a relatively independent tropical Pacific Ocean because the air is heated from the bottom surface instead of the top surface and of much stronger baroclinic instability than the sea and has a very large inter-tropical convergence zone covering the most tropical Pacific Ocean. The idea that it is the wester burst and wind convergence, coming from middle latitudes directly that produce the seawater eastward movement and meridional convergence in the upper levels and result in the typical El Nino sea surface temperature warm signal is confirmed again.

Full Text Available The influence of El Nino / Southern Oscillation (ENSO on the atmospheric concentration of beryllium-7 (7Be in five points situated in South America: Guayaquil, Lima, Anafagasta, Puerto Montt and Punta Arens was investigated. By using correlation analysis it was found that significant statistical relationship between the variability of concentration of 7Be and variability of indices NINO 1+2 and NINO 3 take place in Guayaquil and Puerto Montt. In these cities during the period 1967–1998 yr. there was increased of statistical relationships between the variability of concentration of 7Be and variation of the indices. The results indicate that ENSO most significant effect on the atmospheric concentration of the isotope in the regions located in the subequatorial and subtropical climatic belts. Moreover, such an effect on the time interval 1967–1998 yr., the second half of which corresponds to the period of modern global warming, has increased significantly

One probable extinction and one range reduction of eastern Pacific reef-building hydrocoral ({ital Millepora}) species mark the first documented cases of species eliminations resulting from the worldwide 1980s coral reef bleaching events. Two of 12 Panamanian coral species were eliminated suddenly from their former ranges by prolonged high sea temperatures during the 1982-83 El Nino-Southern Oscillation event. Three conditions contributed to their demise: high sensitivity to sea warming, populations confined to a small geographic area, and bathymetric restriction to the euphotic zone ({le}20 meters depth) where El Nino sea warming had its greatest effect.

Global temperature has increased significantly during the past century. Understanding the causes of observed global temperature change is impossible in the absence of adequate monitoring of changes in global climate forcings and radiative feedbacks. Climate forcings are changes imposed on the planet's energy balance, such as change of incoming sunlight or a human-induced change of surface properties due to deforestation. Radiative feedbacks are radiative changes induced by climate change, such as alteration of cloud properties or the extent of sea ice. Monitoring of global climate forcings and feedbacks, if sufficiently precise and long-term, can provide a very strong constraint on interpretation of observed temperature change. Such monitoring is essential to eliminate uncertainties about the relative importance of various climate change mechanisms including tropospheric sulfate aerosols from burning of coal and oil smoke from slash and burn agriculture, changes of solar irradiance changes of several greenhouse gases, and many other mechanisms. The considerable variability of observed temperature, together with evidence that a substantial portion of this variability is unforced indicates that observations of climate forcings and feedbacks must be continued for decades. Since the climate system responds to the time integral of the forcing, a further requirement is that the observations be carried out continuously. However, precise observations of forcings and feedbacks will also be able to provide valuable conclusions on shorter time scales. For example, knowledge of the climate forcing by increasing CFC's relative to the forcing by changing ozone is important to policymakers, as is information on the forcing by CO2 relative to the forcing by sulfate aerosols. It will also be possible to obtain valuable tests of climate models on short time scales, if there is precise monitoring of all forcings and feedbacks during and after events such as a large volcanic eruption

The prototype camera of the single-mirror Small Size Telescopes (SST-1M) proposed for the Cherenkov Telescope Array (CTA) project has been designed to be very compact and to deliver high performance over thirty years of operation. The camera is composed of an hexagonal photo-detection plane made of custom designed large area hexagonal silicon photomultipliers and a high throughput, highly configurable, fully digital readout and trigger system (DigiCam). The camera will be installed on the telescope structure at the H. Niewodnicza{\\'n}ski institute of Nuclear Physics in Krakow in fall 2015. In this contribution, we review the steps that led to the development of the innovative photo-detection plane and readout electronics, and we describe the test and calibration strategy adopted.

Taking China as the region for test, the potential of the new satellite gravity technique, satellite-to-satellite tracking for improving the accuracy of regional gravity field model is studied. With WDM94 as reference, the gravity anomaly residuals of three models, the latest two GRACE global gravity field model (EIGEN_GRACE02S, GGM02S) and EGM96, are computed and compared. The causes for the differences among the residuals of the three models are discussed. The comparison between the residuals shows that in the selected region, EIGEN_GRACE02S or GGM02S is better than EGM96 in lower degree part (less than 110 degree). Additionally, through the analysis of the model gravity anomaly residuals, it is found that some systematic errors with periodical properties exist in the higher degree part of EIGEN and GGM models, the results can also be taken as references in the validation of the SST gravity data.

The next generation of IACT (Imaging Atmospheric Cherenkov Telescope) will explore the uppermost end of the VHE (Very High Energy) domain up to about few hundreds of TeV with unprecedented sensibility, angular resolution and imaging quality. To this end, INAF (Italian National Institute of Astrophysics) is currently developing a scientific and technological telescope prototype for the implementation of the CTA (Cherenkov Telescope Array) observatory. ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) foresees the full design, development, installation and calibration of a Small Size 4 meter class Telescope. The telescope, named SST-2M, is based on an aplanatic, wide field, double reflection optical layout in a Schwarzschild-Couder configuration. In this paper we report about the technological solutions adopted for the telescope and for the mirrors. In particular the structural and electro-mechanical design of the telescope and the results on the optical performance derived after the development ...

In the present study, the assessment of the Community Atmosphere Model (CAM) developed at National Centre for Atmospheric Research (NCAR) for seasonal forecasting of Indian Summer Monsoon (ISM) with different persistent SST is reported. Towards achieving the objective, 30-year model climatology has been generated using observed SST. Upon successful simulation of climatological features of ISM, the model is tested for the simulation of ISM 2011 in forecast mode. Experiments have been conducted in three different time-phases, viz., April, May and June; using different sets of initial conditions (ICs) and the persistent SSTs of the previous months of the time-phases. The spatial as well as temporal distribution of model simulated rainfall suggest a below normal monsoon condition throughout the season in all the experiments. However, the rainfall anomaly shows some positive signature over north-east part of India in the month of June and August whereas the central Indian landmass had positive anomaly during August and September. The monthly accumulated All-India rainfall (AIR) over land for June to September 2011 are predicted to be 101% (17.6 cm), 86% (24.3 cm), 83% (21.0 cm) and 95% (15.5 cm) of normal AIR, respectively. This makes the seasonal accumulated AIR 78.4 cm which is 11% below the normal rainfall of 87.6 cm. The model prediction for the months of June and July is comparable with the observation; however, the simulation would not be able to capture the high rainfall during August and September. The intention behind this work is to assess the shortcomings in the CAM model prediction, which can later be improved for future monsoon forecast experiments.

The link between sea surface temperature (SST) gradients and atmospheric fronts is explored in a general circulation model across the Gulf Stream (GS) region from December to February 1981-2000. Two model experiments are analyzed, one with a realistic control SST distribution and one with a spatially smoothed SST distribution. The analysis shows a noticeable change in regional atmospheric frontal frequency between the two experiments (up to 30%), with the distribution of change exhibiting a clear imprint of the GS SST front. Further analysis of the surface sensible heat flux gradient across cold fronts reveals the pattern of change to be mediated by a thermal interaction between the oceanic and atmospheric fronts ("thermal damping and strengthening"). These results not only emphasize the significance of the GS SST gradient for storm development in the North Atlantic but also highlight the importance of resolution in assessing the role of frontal air-sea interaction in midlatitude climate variability.

Describes an undergraduate physical science laboratory course exercising the utilization of satellite imagery for studying the floods that resulted in the Parana River region in South America during El Nino (1997-1998), and examines vegetation cover and spectral profiles from the study area in order to further understand and assess the changes…

Useful to learn what is a neutrino. Nino the neutrino travels from the Sun to the Earth with his friends (like a proton and a photon). But not everyone arrives to the INFN Lab's of Gran Sasso in Italy. And someone even can't stop there! This funny cartoon shows the properties of the neutrinos. (It's in Italian with English subtitles).

This paper studies a delayed air-sea coupled oscillator describing the physical mechanism of El Ni(n)o Southern Oscillation.The approximate expansions of the delayed differential equation's solution are obtained successfully by the modified variational iteration method.The numerical results illustrate the effectiveness and correctness of the method by comparing with the exact solution of the reduced model.

Describes an undergraduate physical science laboratory course exercising the utilization of satellite imagery for studying the floods that resulted in the Parana River region in South America during El Nino (1997-1998), and examines vegetation cover and spectral profiles from the study area in order to further understand and assess the changes…

This study uses a twenty-three year (1979-2001) satellite-gauge merged community data set to further describe the relationship between El Nino Southern Oscillation (ENSO) and precipitation. The globally complete precipitation fields reveal coherent bands of anomalies that extend from the tropics to the polar regions. Also, ENSO-precipitation relationships were analyzed during the six strongest El Ninos from 1979 to 2001. Seasons of evolution, Pre-onset, Onset, Peak, Decay, and Post-decay, were identified based on the strength of the El Nino. Then two simple and independent models, first order harmonic and linear, were fit to the monthly time series of normalized precipitation anomalies for each grid block. The sinusoidal model represents a three-phase evolution of precipitation, either dry-wet-dry or wet-dry-wet. This model is also highly correlated with the evolution of sea surface temperatures in the equatorial Pacific. The linear model represents a two-phase evolution of precipitation, either dry-wet or wet-dry. These models combine to account for over 50% of the precipitation variability for over half the globe during El Nino. Most regions, especially away from the Equator, favor the linear model. Areas that show the largest trend from dry to wet are southeastern Australia, eastern Indian Ocean, southern Japan, and off the coast of Peru. The northern tropical Pacific and Southeast Asia show the opposite trend.

of the climatic input. MARX allows stochastic modeling of nonstationary runoff, as runoff anomalies are described by a mixture of autoregressive models with exogenous input, each one corresponding to a climate state. We apply MARX to inflow time series of the Daule Peripa reservoir (Ecuador). El Nino Southern...

To improve the understanding of the single-shell tanks (SSTs) integrity, Washington River Protection Solutions, LLC (WRPS), the USDOE Hanford Site tank contractor, developed an enhanced Single-Shell Tank Integrity Project in 2009. An expert panel on SST integrity, consisting of various subject matters experts in industry and academia, was created to provide recommendations supporting the development of the project. This panel developed 33 recommendations in four main areas of interest: structural integrity, liner degradation, leak integrity and prevention, and mitigation of contamination migration. Seventeen of these recommendations were used to develop the basis for the M-45-10-1 Change Package for the Hanford Federal Agreement and Compliance Order, which is also known as the Tri-Party Agreement. The structural integrity of the tanks is a key element in completing the cleanup mission at the Hanford Site. There are eight primary recommendations related to the structural integrity of Hanford SSTs. Six recommendations are being implemented through current and planned activities. The structural integrity of the Hanford SSTs is being evaluated through analysis, monitoring, inspection, materials testing, and construction document review. Structural evaluation in the form of analysis is performed using modern finite element models generated in ANSYS{reg_sign} The analyses consider in-situ, thermal, operating loads and natural phenomena such as earthquakes. Structural analysis of 108 of 149 Hanford SSTs has concluded that the tanks are structurally sound and meet current industry standards. Analyses of the remaining Hanford SSTs are scheduled for FY2013. Hanford SSTs are monitored through a dome deflection program. The program looks for deflections of the tank dome greater than 1/4 inch. No such deflections have been recorded. The tanks are also subjected to visual inspection. Digital cameras record the interior surface of the concrete tank domes, looking for cracks and

Satellite observations and a high-resolution regional ocean-atmosphere coupled model are used to study the air/sea interactions at the oceanic mesoscale in the Peru-Chile upwelling current system. Coupling between mesoscale sea surface temperature (SST) and wind stress (WS) intensity is evidenced and characterized by correlations and regression coefficients. Both the model and the observations display similar spatial and seasonal variability of the coupling characteristics that are stronger off Peru than off Northern Chile, in relation with stronger wind mean speed and steadiness. The coupling is also more intense during winter than during summer in both regions. It is shown that WS intensity anomalies due to SST anomalies are mainly forced by mixing coefficient anomalies and partially compensated by wind shear anomalies. A momentum balance analysis shows that wind speed anomalies are created by stress shear anomalies. Near-surface pressure gradient anomalies have a negligible contribution because of the back-pressure effect related to the air temperature inversion. As mixing coefficients are mainly unchanged between summer and winter, the stronger coupling in winter is due to the enhanced large-scale wind shear that enables a more efficient action of the turbulent stress perturbations. This mechanism is robust as it does not depend on the choice of planetary boundary layer parameterization.

This paper focuses on using data fusion method to solve the problem that the global sea is not seamlessly covered by the along-track sea surface temperature (SST) data of scanning microwave radiometer on board Haiyang-2A (HY-2A), which is the first ocean dynamic environment satellite of China launched on 16th August 2011. The procedure includes following steps. Firstly, the HY-2A SST data within 200 km of the coastline were identified and removed, the outliers of the HY-2A SST data and the background SST data were also identified and removed. Secondly, the HY-2A SST data were gridded, filtered and corrected. The background SST data were only filtered. Finally, the HY-2A SST data were merged into background SST data by the inverse distance weighted method. Next, the above procedure was tested in the ocean area on the southeast of China. The global 1-km sea surface temperature (G1SST) data were used as the reference data. The results of the procedure with and without the second step were made comparisons, and the results implied that the application of median filter and third-order polynomial curve fitting in the second step could help to improve performance of the merged SST data. The along-track SST data of HY-2A can be merged into OSTIA SST data successfully by the above procedure, and the gaps between tracks were filled up.

Using the SST data series in tropical ocean(20°N-20°S,50°E-80°W)during 1951-1997 to calculate its monthly mean square deviation,the work obtains results showing that interannual SST variability of the Pacific is more significant than that of the Indian Ocean.Especially near the central and eastern equatorial Pacific(165°W-90°W,6°N-6°S）。where it ranges from 2℃ to 4℃.The interannual SST variability is obvious in November and December but small in March and April.The interannual variabiltiy of "warm pool"SST is not so obvious as that of the eastern equatorial Pacific,Howerver,interannual SST variability of the Indian Ocean ranges from 1℃to 2℃ or so,being smaller than that of the Pacific,In the Indian ocean.Interannual SST variability of the Southern Hemisphere is more obvious than that of the Northern Hemisphere,According to above characterstics of interannual SST variability,the key sectors are determined.

Under the recent global warming, melting of arctic sea-ice in recent decades could have contributed to recent climate changes including its long-term trend and extreme weather events. While the climatic response to the sea-ice loss have been studied recently, it is still an open question to what extent the sea-ice change has influenced recent climate change. Other factors, such as for example, SST could also have had an influence. A main objective of GREENICE research project is to show what extent of the observed climate trend as well as observed weather extremes could be explained by the change and variability in sea ice and SST, respectively. In this project, we designed two atmospheric general circulation model experiments: In both experiments observed daily sea ice cover variations are prescribed, while for SST, one experiment uses observed daily variations and the other the observed climatology. The experiment is performed by several different state-of-the-art AGCMs. Our preliminary results show that the observed wintertime temperature trend near the surface is poorly reproduced in our hindcast experiments using observed SIC and SST. The impact of SIC variation seems to be confined near the surface, while SST variation seems a key for temperature trend above. It suggests a necessity to consider the atmospheric poleward energy transport associated with SST variation to understand the observed arctic amplification. Other aspects of SIC/SST impact on the observed circulation change such as NAO shall also be discussed.

Thomson Scattering System (TSS) is the main diagnostic to extract electron temperature and density of steady state superconducting (SST-1) tokamak plasma. Silicon avalanche photo diode is used with low noise and fast signal conditioning electronics (SCE) to detect incoming Thomson scattered laser photons. A stringent requirement for the measurement is to detect high speed and low level light signal (detection of 100 numbers of Thomson scattered photons for 50 ns pulse width at input of active area of detector) in the presence of wide band electro-magnetic interference (EMI) noise. The electronics and instruments for different sub-systems kept in laboratory contribute to the radiated and conductive noise in a complex manner to the experiment, which can degrade the resultant signal to noise ratio (SNR <1). In general a repeated trial method with flexible grounding scheme are used to improve system signal to noise ratio, which is time consuming and less efficient. In the present work a simple, robust, cost-effective instrumentation system is used for the measurement and monitoring with improved ground scheme and shielding method to minimize noise, isolating the internal sub-system generated noise and external interference which leads to an improved SNR.

The ASTRI project is the INAF (Italian National Institute for Astrophysics) flagship project developed in the context of the Cherenkov Telescope Array (CTA) international project. ASTRI is dedicated to the realization of the prototype of a Cherenkov small-size dual-mirror telescope (SST-2M) and then to the realization of a mini-array composed of a few of these units. The prototype and all the necessary hardware devices are foreseen to be installed at the Serra La Nave Observing Station (Catania, Italy) in 2014. The upcoming data flow will be properly reduced by dedicated (online and offline) analysis pipelines aimed at providing robust and reliable scientific results (signal detection, sky maps, spectra and light curves) from the ASTRI silicon photo-multipliers camera raw data. Furthermore, a flexible archiving system has being conceived for the storage of all the acquired ASTRI (scientific, calibration, housekeeping) data at different steps of the data reduction up to the final scientific products. In this c...

The Electron Cyclotron Resonance Heating (ECRH) system is an important heating system for the reliable start-up of tokamak. The 42GHz and 82.6GHz Gyrotron based ECRH systems are used in tokomaks SST-1 and Aditya to carry out ECRH related experiments. The Gyrotrons are high power microwave tubes used as a source for ECRH systems. The Gyrotrons need to be handled with optimum care right from the installation to its Full parameter control operation. The Gyrotrons are associated with the subsystems like: High voltage power supplies (Beam voltage and anode voltage), dedicated crowbar system, magnet, filament and ion pump power supplies and cooling system. The other subsystems are transmission line, launcher and dummy load. A dedicated VME based data acquisition & control (DAC) system is developed to operate and control the Gyrotron and its associated sub system. For the safe operation of Gyrotron, two level interlocks with fail-safe logic are developed. Slow signals that are operated in scale of millisecond range are programmed through software and hardware interlock in scale of microsecond range are designed and developed indigenously. Water-cooling and the associated interlock are monitored and control by data logger with independent human machine interface.

The analyses on the responses of partial pressure difference between sea and air(△PCO2), and total dissolved CO2 concentration (TCO2), to abnormal air-sea event in different seasons, were based on observational data measured during cruises from Nov. 1986 to Dec.1997 in area of 22°N - 18°N, 114°E-130°E. The results indicated that in eyery season, TCO2 was high and △PCO2 was positive during onset and mature period of El Nino, but they were low andnegative respectively during La Nina. Before and after El Nino, partial pressure of CO2 in the sea and air were in the state of equilibrium. Both PCO2 (air) and PCO2 (sw) had same responses to El Nino in each season. PCO2 (air) and PCO2 (sw) were high during mature period of El Nino were low before and in onset period of El Nino; △PCO2 and PCO (sw) reached peak value during El Nino and variation of △PCO2 and PCO2 (sw) were same. The nean exchange of CO2 from sea to air (flux) reached peak value during El Nino in autumn, and decreased during La Nina. Betore and after El Nino the flux is weak, but in opposite direction from air to sea. According to the 1986-1993 average the characteristics of response of TCO2 anomaly to El Nino and La Nina and the range of outstanding variation in different season were discussed. From above it can be deduced some signals showing ENSO event as follows: in Oct. 1995, El Nino of 91/95 was over; In May 1995 it is before a new El Nino; In July 1997 it is in onset of new El Nino; InDec. 1997 it is in the mature stage of El Nino event.

A range of different approaches to data assimilation for Earth's geodynamo are now being pursued, from sequential schemes based on approximate covariances of various degrees of sophistication, to variational methods for models of varying degrees of physical completeness. While variational methods require development of adjoint (and possible tangent linear) variants on the forward code---a challenging programming task for a fully self-consistent modern dynamo code---this approach may ultimately offer significant advantages. For example, adjoint based variational approaches allow initial, boundary, and forcing terms to be explicitly adjusted to combine data from modern and historical eras into dynamically consistent maps of core state, including flow, buoyancy and magnetic fields. Here we describe development of tangent linear and adjoint codes for the Modular Scalable Self-consistent Three-dimensional (MoSST) geodynamo simulator, and present initial results from simple synthetic data assimilation experiments. Our approach has been to develop the exact linearization and adjoint of the actual discrete functions represented by the computer code. To do this we use a 'divide-and-concur' approach: the code is decomposed as the sequential action of a series of linear and non-linear procedures on specified inputs. Non-linear procedures are first linearized about a pre-computed input background state (derived by running the non-linear forward model), and a tangent linear time-step code is developed. For small perturbations of initial state the linearization appears to remain valid for times comparable to the secular variation time-scale. Adjoints for each linear (or linearized) procedure were then developed and tested separately (for symmetry), and then merged into adjoint procedures of increasing complexity. We have completed development of the adjoint for a serial version of the MoSST code, explore time limits of forward operator linearization, and discuss next steps

The single mirror small-size telescope (SST-1M) is one of the telescope projects being proposed for the Cherenkov Telescope Array observatory by a sub-consortium of Polish and Swiss institutions. The SST-1M prototype structure is currently being constructed at the Institute of Nuclear Physics in Cracow, Poland, while the camera will be assembled at the University of Geneva, Switzerland. This prototype enables measurements of parameters having a decisive influence on the telescope performance. We present results of numerical simulations of the SST-1M performance based on such measurements. The telescope effective area, the expected trigger rates and the optical point spread function are calculated.

This document documents the ANSYS axisymmetric parametric model for single-shell tank A and provides sample calculation for analysis-of-record mechanical load conditions. The purpose of this calculation is to develop a parametric model for single shell tank (SST) A, and provide a sample analysis of SST-A tank based on analysis of record (AOR) loads. The SST-A model is based on buyer-supplied as-built drawings and information for the AOR for SSTs, encompassing the existing tank load conditions, and evaluates stresses and deformations throughout the tank and surrounding soil mass.

This document documents the ANSYS axisymmetric parametric model for single-shell tank SX and provides sample calculation for analysis-of-record mechanical load conditions. The purpose of this calculation is to develop a parametric model for single shell tank (SST) SX, and provide a sample analysis of the SST-SX tank based on analysis of record (AOR) loads. The SST-SX model is based on buyer-supplied as-built drawings and information for the AOR for SSTs, encompassing the existing tank load conditions, and evaluates stresses and deformations throughout the tank and surrounding soil mass.

This document documents the ANSYS axisymmetric parametric model for single-shell tank S and provides sample calculation for analysis-of-record mechanical load conditions. The purpose of this calculation is to develop a parametric model for single shell tank (SST) S, and provide a sample analysis of SST-S tank based on analysis of record (AOR) loads. The SST-S model is based on buyer-supplied as-built drawings and information for the AOR for SSTs, encompassing the existing tank load conditions, and evaluates stresses and deformations throughout the tank and surrounding soil mass.

El Ni\\~no exhibits distinct Eastern Pacific (EP) and Central Pacific (CP) types which are commonly, but not always consistently, distinguished from each other by different signatures in equatorial climate variability. Here, we propose an index based on evolving climate networks to objectively discriminate between both flavors by utilizing a scalar-valued evolving climate network measure that quantifies spatial localization and dispersion in El Ni\\~no's associated teleconnections. Our index displays a sharp peak (high localization) during EP events, whereas during CP events (larger dispersion) it remains close to the baseline observed during normal periods. In contrast to previous classification schemes, our approach specifically account for El Ni\\~no's global impacts. We confirm recent El Ni\\~no classifications for the years 1951 to 2014 and assign types to those cases were former works yielded ambiguous results. Ultimately, we study La Ni\\~na episodes and demonstrate that our index provides a similar discrim...

The AIRS Science Team Version-6 data set is a valuable resource for meteorological studies. Quality Controlled earth's surface skin temperatures are produced on a 45 km x 45 km spatial scale under most cloud cover conditions. The same retrieval algorithm is used for all surface types under all conditions. This study used eleven years of AIRS monthly mean surface skin temperature and cloud cover products to show that land surface skin temperatures have decreased significantly in some areas and increased significantly in other areas over the period September 2002 through August 2013. These changes occurred primarily at 1:30 PM but not at 1:30 AM. Cooling land areas contained corresponding increases in cloud cover over this time period, with the reverse being true for warming land areas. The cloud cover anomaly patterns for a given month are affected significantly by El Nino/La Nina activity, and anomalies in cloud cover are a driving force behind anomalies in land surface skin temperature.

The Sydney catchment region encompasses over 16,000km{sup 2}, supplying water to over 4 million inhabitants. However, few studies have investigated the synoptic and climatic influences on inflow in this region, which are crucial for understanding the vulnerability of water supply in a changing climate. This study identifies extremely high and low inflow events between 1960 and 2008 based on catchment averages. The focus of the study is an analysis of the synoptic cause/s of each extreme inflow event. The events are evaluated to identify any trends and also to determine the concurrent significant climatic influences on rainfall over the catchments. Relationships between catchment inflow, rainfall, tropical SST indices, and other influencing factors such as observed wind and temperatures are investigated. Our results show that East Coast Lows and anomalously easterly flow are the drivers of high inflow events, with low inflow events dominated by westerly wind patterns and the El Nino-Southern Oscillation.

National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes SST anomaly data using a combination of the POES AVHRR Global Area Coverage data, and data from a climatological database by Casey and...

National Oceanic and Atmospheric Administration, Department of Commerce — A 271 year record of Sr/Ca variability in a coral from Rarotonga in the South Pacific gyre. Calibration with monthly sea surface temperature (SST) from satellite and...

National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes SST anomaly data using a combination of the POES AVHRR Global Area Coverage data, and data from a climatological database by Casey and...

In this letter, we evaluate to which extent the activity of ocean fronts can be retrieved from the geometric regularity of ocean tracer observations. Applied to sea surface temperature (SST), we propose a method for the characterization of this geometric regularity from curvature-based statistics along temperature level lines in front regions. To assess the effectiveness of the proposed descriptors, we used six years (from 2003 to 2008) of daily SST observations of the regions of Agulhas in t...

We assess internally-generated climate variability expressed by a multi-model ensemble of unperturbed climate simulations. We focus on basin-scale annual-average sea surface temperatures (SSTs) from twenty multicentennial pre-industrial control simulations contributing to the fifth phase of the Coupled Model Intercomparison Project. Ensemble spatial patterns of regional modes of variability and ensemble (cross-)wavelet-based phase-frequency diagrams of corresponding paired indices summarize the ensemble characteristics of inter-basin and regional-to-global SST interactions on a broad range of timescales. Results reveal that tropical and North Pacific SSTs are a source of simulated interannual global SST variability. The North Atlantic-average SST fluctuates in rough co-phase with the global-average SST on multidecadal timescales, which makes it difficult to discern the Atlantic Multidecadal Variability (AMV) signal from the global signal. The two leading modes of tropical and North Pacific SST variability converge towards co-phase in the multi-model ensemble, indicating that the Pacific Decadal Oscillation (PDO) results from a combination of tropical and extra-tropical processes. No robust inter- or multi-decadal inter-basin SST interaction arises from our ensemble analysis between the Pacific and Atlantic oceans, though specific phase-locked fluctuations occur between Pacific and Atlantic modes of SST variability in individual simulations and/or periods within individual simulations. The multidecadal modulation of PDO by the AMV identified in observations appears to be a recurrent but not typical feature of ensemble-simulated internal variability. Understanding the mechanism(s) and circumstances favoring such inter-basin SST phasing and related uncertainties in their simulated representation could help constraining uncertainty in decadal climate predictions.

An interdecadal shift in summer (June-August) sea surface temperature (SST) variations during the period of 1968―2002 was identified in the late 1980s, which is characterized by a phase alternating from negative to positive phases of the leading mode of the empirical orthogonal function (EOF) analysis of the summer monthly mean SST in the Pacific domain 100°―180°E and 0°―40°N, accounting for 30.5% of the total variance. During the period of 1968―1987, the leading mode with a mean negative phase state (mean standard deviation = -0.586) controlled SST variability in the western North Pacific. Correspondingly, negative SST anomalies occupied the western North Pacific south of Japan and Chinese marginal seas. During the period of 1988―2002, the leading mode shifted to its strong positive polarity (mean standard deviation = 0.781), thus positive SST anomalies appeared in the western North Pacific. Accompanied by the interdecadal shift in summer mean SST, summer mean rainfall increased in southern and southeastern China during the late period, particularly in southeastern China where increase in summer mean rainfall exceeded 40 mm, at the 0.05 significance level.

Most of the study on correlation between the subtropical high and SST focus on the location or intensity of the former versus the latter. It is worthwhile to work on links other than what is usually addressed to identify guidelines in the prediction of the subtropical high. Based on the analysis of subtropical high in west Pacific summer and its correlation with SST in equatorial and north Pacific from previous December to subsequent November, correlation between the area index, west-extending point, location of the subtropical high ridge and SST is discussed. It is conducted by looking into the confidence level of gridpoints and their percentage in the total and examining how they vary with time. From the point of intensity and movement/expansion, feedbacks from the subtropical high to SST are also studied. The SST affects the subtropical high just as the subtropical high affects the SST. A linkage model is thus set up to assist the making of summer rainfall prediction in China's raining seasons.

Complex network theory provides a powerful toolbox for studying the structure of statistical interrelationships between multiple time series in various scientific disciplines. In this work, we apply the recently proposed climate network approach for characterizing the evolving correlation structure of the Earth's climate system based on reanalysis data of surface air temperatures. We provide a detailed study on the temporal variability of several global climate network characteristics. Based on a simple conceptual view on red climate networks (i.e., networks with a comparably low number of edges), we give a thorough interpretation of our evolving climate network characteristics, which allows a functional discrimination between recently recognized different types of El Ni\\~no episodes. Our analysis provides deep insights into the Earth's climate system, particularly its global response to strong volcanic eruptions and large-scale impacts of different phases of the El Ni\\~no Southern Oscillation (ENSO).

Twelve homes were constructed in 1949 at the top of a sea cliff along Esplanade Drive in the City of Pacifica, located on the northern coast of San Mateo County, California. During the heavy storms of the 1997/98 El Nino winter, a severe episode of cliff retreat undermined seven homes and threatened three others. The geologic, tide, wave, rainfall and wind data were analyzed to determine the causes of this erosion events.

A new type of EI Nino event has been identified in the last decade. During "warm pool" EI Nino (WPEN) events, sea surface temperatures (SSTs) in the central equatorial Pacific are warmer than average. The EI Nino signal propagates poleward and upward as large-scale atmospheric waves, causing unusual weather patterns and warming the polar stratosphere. In austral summer, observations show that the Antarctic lower stratosphere is several degrees (K) warmer during WPEN events than during the neutral phase of EI Nino/Southern Oscillation (ENSO). Furthermore, the stratospheric response to WPEN events depends of the direction of tropical stratospheric winds: the Antarctic warming is largest when WPEN events are coincident with westward winds in the tropical lower and middle stratosphere i.e., the westward phase of the quasi-biennial oscillation (QBO). Westward winds are associated with enhanced convection in the subtropics, and with increased poleward wave activity. In this paper, a new formulation of the Goddard Earth Observing System Chemistry-Climate Model, Version 2 (GEOS V2 CCM) is used to substantiate the observed stratospheric response to WPEN events. One simulation is driven by SSTs typical of a WPEN event, while another simulation is driven by ENSO neutral SSTs; both represent a present-day climate. Differences between the two simulations can be directly attributed to the anomalous WPEN SSTs. During WPEN events, relative to ENSO neutral, the model simulates the observed increase in poleward planetary wave activity in the South Pacific during austral spring, as well as the relative warming of the Antarctic lower stratosphere in austral summer. However, the modeled response to WPEN does not depend on the phase of the QBO. The modeled tropical wind oscillation does not extend far enough into the lower stratosphere and upper troposphere, likely explaining the model's insensitivity to the phase of the QBO during WPEN events.

In electric power system operation and dam management, it is important that we forecast the rainfall depth in the rainy season. This paper studies the technique using neural network in order to forecast the amount of rainfall in rainy season on upper district of dam for hydro power plant. A case study was carried out on Central Japan. We were able to confirm the effectiveness of the information obtained from El Nino and La Nina data.

The El Nino and La Nina have been found to influence the weather at a remote place. In this paper, the authors investigate the impact of El Nino & La Nina on the surface temperature and rainfall over few selected locations in India and abroad. The study shows that the ENSO affects the surface rainfall; however, the impact is not the same over all the locations. In order to find out whether such influence is latitude sensitive, the study has been performed over locations located at different latitudes and at a fixed longitude. To check if the El Nino/La Nina leaves any impressions on the upper air meteorological elements, the cloud liquid water (CLW), precipitation water (PW), latent heat (LH), freezing level height (HFL) and the bright band height (BBH) over a few locations have been studied from the Earth's surface up to a height of 18 km above. The CLW, PW and LH values have been obtained from the data product 2A12 of the Tropical Microwave Imager (TMI) onboard the Tropical Rainfall Measuring Satellite (TRMM), while that of the BBH and the HFL are obtained from the data product 2A23 of the precipitation radar (PR) onboard the TRMM.

To improve the understanding of the single-shell tanks (SSTs) integrity, Washington River Protection Solutions, LLC (WRPS), the USDOE Hanford Site tank contractor, developed an enhanced Single-Shell Tank Integrity Project (SSTIP) in 2009. An expert panel on SST integrity, consisting of various subject matters experts in industry and academia, was created to provide recommendations supporting the development of the project. This panel developed 33 recommendations in four main areas of interest: structural integrity, liner degradation, leak integrity and prevention, and mitigation of contamination migration, Seventeen of these recommendations were used to develop the basis for the M-45-10-1 Change Package for the Hanford Federal Agreement and Compliance Order, which is also known as the Tri-Party Agreement. The structural integrity of the tanks is a key element in completing the cleanup mission at the Hanford Site. There are eight primary recommendations related to the structural integrity of Hanford Single-Shell Tanks. Six recommendations are being implemented through current and planned activities. The structural integrity of the Hanford is being evaluated through analysis, monitoring, inspection, materials testing, and construction document review. Structural evaluation in the form of analysis is performed using modern finite element models generated in ANSYS. The analyses consider in-situ, thermal, operating loads and natural phenomena such as earthquakes. Structural analysis of 108 of 149 Hanford Single-Shell Tanks has concluded that the tanks are structurally sound and meet current industry standards. Analysis of the remaining Hanford Single-Shell Tanks is scheduled for FY2014. Hanford Single-Shell Tanks are monitored through a dome deflection program. The program looks for deflections of the tank dome greater than 1/4 inch. No such deflections have been recorded. The tanks are also subjected to visual inspection. Digital cameras record the interior surface of

Our previous results have shown that somatostatin receptor subtype SST(2A) is responsible for thermal, but not mechanical nociceptive transmission in the rat spinal cord. The present study was undertaken to further examine the ultrastructural localization of SST(2A) receptor in lamina II of the spinal dorsal horn and the role of SST(2A) receptor in thermal hyperalgesia following Complete Freund's Adjuvant (CFA)-induced inflammation. We found that SST(2A) receptors in lamina II are located primarily in postsynaptic dendrites and soma, but not in axons or synaptic terminals. CFA-induced inflammation markedly increased SST(2A) receptor-like immunoreactivity in lamina II. Paw withdrawal latency (PWL) evoked by noxious heating was obviously shortened 1 h after intraplantar injection of CFA, exhibiting thermal hyperalgesia. Pre-blocking SST(2A) activity by intrathecal pre-administration of CYN154806, a broad-spectrum antagonist of SST(2) receptor, or specific antiserum against SST(2A) receptor (anti-SST(2A)) significantly attenuated thermal hyperalgesia in a dose-dependent fashion in CFA-treated rats. But, administration of anti-SST(2A) or CYN154806 after CFA treatment had no effect upon thermal hyperalgesia. Intrathecal application of SST(2A) agonist SOM-14 at different doses prior to CFA treatment did not influence thermal hyperalgesia in inflamed rats, but at a low dose shortened PWL evoked by noxious heating in normal rats. These results suggest that spinal SST(2A) receptors play a key role in triggering the generation, but not maintenance, of thermal hyperalgesia evoked by CFA-induced inflammation. The up-regulation of SST(2A) receptors in the spinal cord may be one of the mechanisms underlying inflammation-induced thermal hyperalgesia.

Most of the current coupled general circulation models show a strong warm bias in the eastern Tropical Atlantic. In this paper, various sensitivity experiments with the Kiel Climate Model (KCM) are described. A largely reduced warm bias and an improved seasonal cycle in the eastern Tropical Atlantic are simulated in one particular version of KCM. By comparing the stable and well-tested standard version with the sensitivity experiments and the modified version, mechanisms contributing to the reduction of the eastern Atlantic warm bias are identified and compared to what has been proposed in literature. The error in the spring and early summer zonal winds associated with erroneous zonal precipitation seems to be the key mechanism, and large-scale coupled ocean-atmosphere feedbacks play an important role in reducing the warm bias. Improved winds in boreal spring cause the summer cooling in the eastern Tropical Atlantic (ETA) via shoaling of the thermocline and increased upwelling, and hence reduced sea surface temperature (SST). Reduced SSTs in the summer suppress convection and favor the development of low-level cloud cover in the ETA region. Subsurface ocean structure is shown to be improved, and potentially influences the development of the bias. The strong warm bias along the southeastern coastline is related to underestimation of low-level cloud cover and the associated overestimation of surface shortwave radiation in the same region. Therefore, in addition to the primarily wind forced response at the equator both changes in surface shortwave radiation and outgoing longwave radiation contribute significantly to reduction of the warm bias from summer to fall. (orig.)

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) raise difficult therapeutic problems despite the emergence of targeted therapies. Somatostatin analogs (SSA) remain pivotal therapeutic drugs. However, the tachyphylaxis and the limited antitumoral effects observed with the classical somatostatin 2 (sst2) agonists (octreotide and lanreotide) led to the development of new SSA, such as the pan sst receptor agonist pasireotide. Our aim was to compare the effects of pasireotide and octreotide on cell survival, chromogranin A (CgA) secretion, and sst2 phosphorylation/trafficking in pancreatic NET (pNET) primary cells from 15 tumors. We established and characterized the primary cultures of human pancreatic tumors (pNETs) as powerful preclinical models for understanding the biological effects of SSA. At clinically relevant concentrations (1-10 nM), pasireotide was at least as efficient as octreotide in inhibiting CgA secretion and cell viability through caspase-dependent apoptosis during short treatments, irrespective of the expression levels of the different sst receptors or the WHO grade of the parental tumor. Interestingly, unlike octreotide, which induces a rapid and persistent partial internalization of sst2 associated with its phosphorylation on Ser341/343, pasireotide did not phosphorylate sst2 and induced a rapid and transient internalization of the receptor followed by a persistent recycling at the cell surface. These results provide the first evidence, to our knowledge, of striking differences in the dynamics of sst2 trafficking in pNET cells treated with the two SSAs, but with similar efficiency in the control of CgA secretion and cell viability.

Long pulse (of the order of 1000 s or more) SST-1 tokamak experiments demand a data acquisition system that is capable of acquiring data from various diagnostics channels without losing useful data (and hence physics information) while avoiding unnecessary generation of a large volume data. SST-1 Phase-1 tokamak operation has been envisaged with data acquisition of several essential diagnostics channels. These channels demand data acquisition at a sampling rate ranging from 1 kilo samples per second (KSPS) to 1 mega samples per second (MSPS). Considering the technical characteristics and requirements of the diagnostics, a data acquisition system based on PXI and CAMAC has been developed for SST-1 plasma diagnostics. Both these data acquisition systems are scalable. Present data acquisition needs involving slow plasma diagnostics are catered by the PXI based data acquisition system. On the other hand, CAMAC data acquisition hardware meets all requirements of the SST-1 Phase-1 fast plasma diagnostics channels. A graphical user interface for both data acquisition systems (PXI and CAMAC) has been developed using LabVIEW application development software. The collected data on the local hard disk are directly streaming to the central server through a dedicated network for post-shot data analysis. This paper describes the development and integration of the data acquisition system for SST-1 Phase-1 plasma diagnostics. The integrated testing of the developed data acquisition system has been performed using SST-1 central control and diagnostics signal conditioning units. In the absence of plasma shots, the integrated testing of the data acquisition system for the initial diagnostics of SST-1 Phase-1 operation has been performed with simulated physical signals. The primary engineering objective of this integrated testing is to validate the performance of the developed data acquisition system under simulated conditions close to that of actual tokamak operation. The data

Although the influence of the anomalous midlatitude SST upon atmospheric local circulation has been getting common in particular over the Kuroshio and the Gulf Stream regions, observational studies on the influence of the Okhotsk Sea, which is to the north of the Kuroshio, upon the atmospheric local circulation is much less than those of the Kuroshio. The climate of the Okhotsk SST is very peculiar. Extremely cold SST spots, whose summertime SST is lower than 5 Celsius degrees, are formed around Kuril Islands. Because SSTs are generally determined by local air-sea interaction as well as temperature advection, it is very difficult to isolate only the oceanic influence upon the atmosphere. The SST in this cold spot is, however, dominated by the tidal mixing, which is independent of the atmospheric processes. This unique condition may ease the account for the oceanic influence only. Although the SST environment of the Okhotsk Sea is good for understanding the oceanic influence upon the atmosphere, only a few studies has been executed in this region because of the difficulty of observations by research vessels in this region, where territory problems between Japan and Russia is unsolved. Because of the scant of direct observation, the Okhotsk Sea was still mysterious. In 2006 August, GPS radiosonde observation was carried out by Russian research vessel Khromov in the Sea of Okhotsk by the cooperation between Japan and Russia, and strong SST gradient of about 7 Celsius degrees/10km was observed around the Kuril Islands. The purpose of this study is to demonstrate observational finding of meso-scale atmospheric anticyclonic circulation influenced by the cold oceanic spot around the Kuril Island. The summaries of the observation are as follows. Meso-scale atmospheric ageostrophic anticyclonic circulation in the atmospheric marine-boundary layer is observed in and around the cold spot. A high air pressure area as compared with other surrounding areas is also located at the

Full Text Available Somatostatin (SST, cortistatin (CORT, and its receptors (sst1-5, and ghrelin and its receptors (GHS-R are two highly interrelated neuropeptide systems with a broad range of overlapping biological actions at central, cardiovascular and immune levels among others. Besides their potent regulatory role on GH release, its endocrine actions are highlighted by SST/CORT and ghrelin influence on insulin secretion, glucose homeostasis and insulin resistance. Interestingly, most components of these systems are expressed at the endocrine pancreas and are actively involved in the modulation of pancreatic islet function and, consequently influence glucose homeostasis. In addition, some of them also participate in islet survival and regeneration. Furthermore, under severe metabolic condition as well as in endocrine pathologies, their expression profile is severely deregulated. These finding suggest that SST/CORT and ghrelin systems could play a relevant role in pancreatic function under metabolic and endocrine pathologies. Accordingly, these systems have been therapeutically targeted for the prevention or amelioration of certain metabolic conditions (obesity as well as for tumor growth inhibition and/or hormonal regulation in endocrine pathologies (neuroendocrine tumors. This review focuses on the interrelationship between SST/CORT and ghrelin systems and their role in severe metabolic conditions and some endocrine disorders.

The interannual-to-interdecadal relationship between the Pacific sea surface temperature (SST) and the northern hemispheric midlatitude's atmosphere represented by the circumpolar vortex was documented with the global oceanic and atmospheric reanalysis data of recent 50 years.Two covarying modes of the Pacific SST and northern circumpolar vortex anomalies during winter were examined using the singular value decomposition and wavelet analysis techniques.One is the interannual,ENSO-related mode and the other is the interdecadal,North Pacific SST-related mode with a period of around 20 years.The two modes exhibit distinct spatial structures.For the interannual mode,the SST anomaly is characterized by a typical ENSO pattern with the principal signature in the tropical eastern Pacific and secondary one in the central North Pacific,while the atmospheric anomaly is regional,characterized by a Pacific-North American pattern.For the interdecadal mode,large SST anomaly is located in the central North Pacific,while the atmospheric anomaly is zonally global,associated with the midlatitute's standing long-wave variations.When the central North Pacific is colder,the long-wave is stronger,and vice versa.Further investigations suggest that the interdecadal mode could involve an interaction between "two oceans and an atmosphere".

The coupling between sea surface temperature (SST) and sea surface wind speed over mesoscale eddies in the South China Sea (SCS) was studied using satellite measurements. Positive correlations between SST anomalies (SSTA) and wind speed anomalies were found over both cyclonic and anticyclonic eddies. In contrast to the open oceans, the spatial patterns of the coupling over mesoscale eddies in the SCS depend largely on the seasonal variations of the background SST gradient, wind speed, and wind directional steadiness. In summer, the maximum SSTA location coincides with the center of eddy-induced sea surface height anomalies. In winter, the eddy-induced SSTA show a clear dipole pattern. The spatial patterns of wind speed anomalies over eddies are similar to those of the SSTA in both seasons. Wind speed anomalies are linearly correlated with SSTA over anticyclonic and cyclonic eddies. The coupling coefficients between SSTA and wind speed anomalies in the SCS are comparable to those in the open oceans.

The authors examine the Indian Ocean sea surface temperature （SST） biases simulated by a Flexible Regional Ocean Atmosphere Land System （FROALS） model. The regional coupled model exhibits pronounced cold SST biases in a large portion of the Indian Ocean warm pool. Negative biases in the net surface heat fluxes are evident in the model, leading to the cold biases of the SST. Further analysis indicates that the negative biases in the net surface heat fluxes are mainly contributed by the biases of sensible heat and latent heat flux. Near-surface meteorological variables that could contribute to the SST biases are also examined. It is found that the biases of sensible heat and latent heat flux are caused by the colder and dryer near-surface air in the model.

Covariance error analysis techniques were applied to investigate estimation strategies for the high-low SST mission for accurate local recovery of gravitational fine structure, considering the aliasing effects of unsolved for parameters. Surface density blocks of 5 deg x 5 deg and 2 1/2 deg x 2 1/2 deg resolution were utilized to represent the high order geopotential with the drag-free GRAVSAT configured in a nearly circular polar orbit at 250 km. altitude. GEOPAUSE and geosynchronous satellites were considered as high relay spacecraft. It is demonstrated that knowledge of gravitational fine structure can be significantly improved at 5 deg x 5 deg resolution using SST data from a high-low configuration with reasonably accurate orbits for the low GRAVSAT. The gravity fine structure recoverability of the high-low SST mission is compared with the low-low configuration and shown to be superior.

Highlights: • SST-1 Tokamak was successfully commissioned. • Vacuum vessel was pumped down to 4.5 × 10{sup –8} mbar after baking and continuous GDC. • GDC reduced the water vapour by additional 57% while oxygen was reduced by 50%. • Under this condition, an initial plasma breakdown with current of 40 kA for 75 ms was achieved. - Abstract: Steady-state Superconducting Tokamak (SST-1) vacuum vessel (VV) adopts moderate baking at 110 ± 10 °C and the limiters baking at 250 ± 10 °C for ∼ 200 h followed by glow discharge cleaning in hydrogen (GDC-H) with 0.15 A/m{sup 2} current density towards its conditioning prior to plasma discharge experiment. The baking in SST-1 reduces the water (H{sub 2}O) vapor by 95% and oxygen (O{sub 2}) by 60% whereas the GDC reduces the water vapor by an additional 57% and oxygen by another 50% as measured with residual gas analyzer. The minimum breakdown voltage for H-GDC in SST-1 tokamak was experimentally observed to 300 V at 8 mbar cm. As a result of these adherences, SST-1 VV achieves an ultimate of 4.5 × 10{sup −8} mbar with two turbo-molecular pumps with effective pumping speed of 3250 l/s. In the last campaign, SST-1 has achieved successful plasma breakdown, impurity burn through and a plasma current of ∼ 40 kA for 75 ms.

Five year (2010-2014) Advanced Very High Resolution Radiometer (AVHRR) sea surface temperature (SST) data produced by the Australian Bureau of Meteorology have been validated against drifting buoy data and then used to study the seasonal patterns of the SST diurnal variation (DV) events over the Tropical Warm Pool region (TWP, 25°S-15°N, 90°E-170°E). The in situ validation results illustrate the overall good quality of the AVHRR SST data set, although an average 0.19 K underestimation of the daytime measurements has been observed. The nighttime observations are in good agreement with in situ buoys with an average bias of 0.03 and a 0.30 K standard deviation of the biases. This SST data set is then used to characterize the SST DV seasonal patterns, together with wind speeds, daily maximum solar shortwave insolation (SSImax), and latent heat flux (LHF). A double-peak seasonal pattern of SST DV is observed over the study region: the strongest DVs are found in March and October and the weakest in June. Sensitivity tests of DV to wind, SSImax, and LHF are conducted. The results indicate (1) different morning and early afternoon winds (7 A.M. to 2 P.M. local time, LT) affect DV by as much as 0.73 K when the half-daily (defined as 2 A.M. to 2 P.M. LT in this study) average winds are fixed between 2 and 3 m s-1; (2) SSImax levels regulate DV less significantly (<0.68 K) under fixed winds; and (3) LHF effects on DV are relatively weak (<0.35 K).

derived products. It is quite natural that the relationship, in general, resembled one another in the left and right panels except that of SST and D q with LHF, where the mean trend appears to be opposite (figure 3 (a),(b),(e),(f)). The reason...C and 2ms 21 , respectively and underestimates the humidity gradient by 2 g kg 21 (figure 6(b),(d),(f)). The process of underestimation of SST below 28.5uC, therefore, induces high LHF by invoking the thumb rule proposed by Zhang and McPhaden (1995...

The differences in tropical air-sea interactions and global climate connection as well as the hindcast skills for the warm pool (WP) and cold tongue (CT) El Ninos are investigated based on observed, (re)analyzed, and model hindcast data. The robustness of observed global climate connection is established from the model simulations. Lastly, variations of atmosphere and ocean conditions in the recent decades, and their possible connection with the frequency increase of the WP El Nino are discussed. Consistent with previous results, our individual case study and composite results suggest that stronger (weaker) and more eastward extended (westward confined) westerly wind along the equatorial Pacific in early months of a year is associated with active (suppressed) air-sea interaction over the cold tongue/the Intertropical Convergence Zone complex, as well as more (less) intensive oceanic thermocline feedback, favoring the CT (WP) El Nino development. The preceding westerly wind signal and air-sea interaction differences may be responsible for the predication skill difference with higher (lower) overall hindcast skill for the CT (WP) El Nino in the Climate Forecast System of National Centers for Environmental Prediction. Our model experiments show that, in addition to the tropics, the eastern Pacific, North America and North Atlantic are the major regions having robust climate differences between the CT and WP El Ninos. Nevertheless, the climate contrasts seem not robust over the Eurasian continent. Also, the frequency increase of the WP El Nino in the recent decades may not be directly connected with the linear trend of the tropical climate. (orig.)

It has long been known that generally the warmer the sea surface temperature (SST), the more possible tropical cyclone (TC) genesis is, assuming the atmosphere is supportive. The conventional wisdom has been that - apart from what the TC cools through upwelling -- one value of SST represents the state of the ocean surface in the region of the storm's inner circulation. With the advent of the satellite era and fine resolution SST datasets now becoming available, we know that in reality there are gradients of SST across which developing TCs move. The influence of those gradients on tropical convection and TCs is largely unknown at this time. Previous studies have shown that SST gradients can significantly impact the overlying ocean surface winds leading to areas of enhanced convergence/divergence and Vorticity (Chelton et al. 2004; O'Neill et al. 2005, 2010). The magnitude of this effect approximately increases as the surface wind increases. Work by Minobe et al. (2008) concluded that a sharp SST Gradient, over the Gulf Stream for instance, could produce enough surface wind convergence to maintain a band of precipitation along the ocean front. The authors seek to understand whether the conclusions made in previous works can be applied in the case of a TC. To address this, the effects of an idealized sea surface temperature (SST) gradient on a simulated TC are investigated using the Weather Research and Forecasting (WRF) model at 2km grid spacing. An idealized analytic vortex with no accompanying background wind is used to simulate the TC in one run with a horizontal north-south SST gradient and in a second run with the SST gradient flipped south-north. A third model run with constant 28oC SST everywhere is also conducted. Model runs with the SST gradient show asymmetries in convection and structure develop quickly before and after the cyclone develops. In these runs the cyclone drifts one direction depending on the location of colder SST. This is consistent with a

Full Text Available Somatostatin receptors (ssts are expressed in thyroid cancer cells, but their biological significance is not well understood. The aim of this study was to assess ssts in well differentiated (WDTC and poorly differentiated thyroid cancer (PDTC by means of imaging and molecular tools and its relationship with the efficacy of somatostatin analog treatment. Thirty-nine cases of thyroid carcinoma were evaluated (20 PDTC and 19 WDTC. Depreotide scintigraphy and mRNA levels of sst-subtypes, including the truncated variant sst5TMD4, were carried out. Depreotide scans were positive in the recurrent tumor in the neck in 6 of 11 (54% PDTC, and in those with lung metastases in 5/11 cases (45.4%; sst5TMD4 was present in 18/20 (90% of PDTC, being the most densely expressed sst-subtype, with a 20-fold increase in relation to sst2. In WDTC, sst2 was the most represented, while sst5TMD4 was not found; sst2 was significantly increased in PDTC in comparison to WDTC. Five depreotide positive PDTC received octreotide for 3-6 months in a pilot study with no changes in the size of the lesions in 3 of them, and a significant increase in the pulmonary and cervical lesions in the other 2. All PDTC patients treated with octreotide showed high expression of sst5TMD4. ROC curve analysis demonstrated that only sst5TMD4 discriminates between PDTC and WDTC. We conclude that sst5TMD4 is overexpressed in PDTC and may be involved in the lack of response to somatostatin analogue treatment.

Using the middle atmosphere temperature data set observed by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) satellite experiment between 2002 and 2012, and temperatures simulated by the Whole Atmospheric Community Climate Model version 3.5 (WACCM3.5) between 1953 and 2005, we studied the influence of El Niño-Southern Oscillation (ENSO) on middle atmosphere temperature during the Northern Hemisphere (NH) wintertime. For the first time, a significant winter temperature response to ENSO in the middle mesosphere has been observed, with an anomalous warming of approximately 1.0 K/MEI (Multivariate ENSO Index) in the tropics and an anomalous cooling of approximately 2.0 K/MEI in the NH middle latitudes. The observed temperature responses to ENSO in the mesosphere are opposite to those in the stratosphere, in agreement with previous modeling studies. Temperature responses to ENSO observed by SABER show similar patterns to those simulated by the WACCM3.5 model. Analysis of the WACCM3.5 residual mean meridional circulation response to ENSO reveals a significant downwelling in the tropical mesosphere and upwelling in the NH middle and high latitudes during warm ENSO events, which is mostly driven by anomalous eastward gravity wave forcing in the NH mesosphere.

Using the middle atmosphere temperature data set observed by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) satellite experiment between 2002 and 2012, and temperatures simulated by the Whole Atmospheric Community Climate Model version 3.5 (WACCM3.5) between 1953 and 2005, we studied the influence of El Niño-Southern Oscillation (ENSO) on middle atmosphere temperature during the Northern Hemisphere (NH) wintertime. For the first time, a significant winter temperature response to ENSO in the middle mesosphere has been observed, with an anomalous warming of approximately 1.0 K/MEI (Multivariate ENSO Index) in the tropics and an anomalous cooling of approximately 2.0 K/MEI in the NH middle latitudes. The observed temperature responses to ENSO in the mesosphere are opposite to those in the stratosphere, in agreement with previous modeling studies. Temperature responses to ENSO observed by SABER show similar patterns to those simulated by the WACCM3.5 model. Analysis of the WACCM3.5 residual mean meridional circulation response to ENSO reveals a significant downwelling in the tropical mesosphere and upwelling in the NH middle and high latitudes during warm ENSO events, which is mostly driven by anomalous eastward gravity wave forcing in the NH mesosphere.

Satellite SST (sea surface temperature) from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) is compared with in situ temperature observations from Argo profiling floats over the global oceans to evaluate the advantages of Argo NST (near-surface temperature: water temperature less than 1 m from the surface). By comparing Argo nominal surface temperature ( 5 m) with its NST, a diurnal cycle caused by daytime warming and nighttime cooling was found, along with a maximum warming of 0.08±0.36°C during 14:00-15:00 local time. Further comparisons between Argo 5-m temperature/Argo NST and AMSR-E SST retrievals related to wind speed, columnar water vapor, and columnar cloud water indicate warming biases at low wind speed (28 mm during daytime. The warming tendency is more remarkable for AMSR-E SST/Argo 5-m temperature compared with AMSR-E SST/Argo NST, owing to the effect of diurnal warming. This effect of diurnal warming events should be excluded before validation for microwave SST retrievals. Both AMSR-E nighttime SST/Argo 5-m temperature and nighttime SST/Argo NST show generally good agreement, independent of wind speed and columnar water vapor. From our analysis, Argo NST data demonstrated their advantages for validation of satellite-retrieved SST.

There is an increasing demand for accurate prognostication for colorectal cancer (CRC). This study sought to assess prognostic potentials of methylation targets in the serum of CRC patients. A total of 165 CRC patients were enrolled in this prospective study. Promoter methylation levels of seven genes in pre-operative sera and matched tumor tissues were evaluated by quantitative methylation-specific PCR. Kaplan-Meier test, and univariate and multivariate Cox proportional hazards regression models were used for survival analyses. After a median follow-up of 56 months, 43 patients (28.7%) experienced tumor recurrence. In univariate survival analyses, serum methylation levels of SST and MAL were significantly predictive of cancer-specific death (Pcancer death and recurrence, respectively). When focusing on stage II and III patients, prognostication with serum methylated SST remained significant. Methylated SST detected in all serum samples can be traced back to the matched primary tumor tissues. We believe that methylated SST detected in the pre-operative sera of CRC patients appear to be a novel promising prognostic marker and probably can be auxiliary to tumor staging system and serum carcinoembryonic antigen towards better risk stratification.

Graphite plasma facing components (PFCs) were installed inside the SST-1 vacuum vessel. Prior to installation, all the graphite tiles were baked at 1000 °C in a vacuum furnace operated below 1.0 × 10-5 mbar. However due to the porous structure of graphite, they absorb a significant amount of water vapour from air during the installation process. Rapid desorption of this water vapour requires high temperature bake-out of the PFCs at ≥ 250 °C. In SST-1 the PFCs were baked at 250 °C using hot nitrogen gas facility to remove the absorbed water vapour. Also device with large graphite surface area has the disadvantage that a large quantity of hydrogen gets trapped inside it during plasma discharges which makes density control difficult. Helium glow discharge cleaning (He-GDC) effectively removes this stored hydrogen as well as other impurities like oxygen and hydrocarbon within few nano-meters from the surface by particle induced desorption. Before plasma operation in SST-1 tokamak, both baking of PFCs and He-GDC were carried out so that these impurities were removed effectively. The mean desorption yield of hydrogen was found to be 0.24. In this paper the results of baking and He-GDC experiments of SST-1 will be presented in detail.

Unlike most mammals, birds do not need to synchronize copulation with ovulation. Hens are endowed with tubular structures, the sperm-storage tubules (SST), in their oviducts which the sperm enter and survive for weeks after mating or artificial insemination. Sperm are slowly but continually releas...

Sea surface temperature (SST) variation provides vital information for weather and ocean forecasting especially when studying climate change. Conventional methods of collecting ocean parameters such as SST, remains expensive and labor intensive due to the large area coverage and complex analytical procedure required. Therefore, some studies need to be conducted on the spatial and temporal distribution of ocean parameters. This study looks at Geo-statisctical methods in interpolating SST values and its impact on accuracy. Two spatial Geo-statistical techniques, mainly kriging and inverse distance functions (IDW) were applied to create variability distribution maps of SST for the Southern South China Sea (SCS). Data from 72 sampling station was collected in July 2012 covering an area of 270 km x 100 km and 263 km away from shore. This data provide the basis for the interpolation and accuracy analysis. After normalization, variograms were computed to fit the data sets producing models with the least RSS value. The accuracy were later evaluated based on on root mean squared error (RMSE) and root mean kriging variance (RMKV). Results show that Kriging with exponential model produced most accuracy estimates, reducing error in 17.3% compared with inverse distance functions.

Full Text Available The annual cycle of sea surface temperature (SST in the eastern equatorial Pacific (EEP with the largest amplitude in the tropical oceans is poorly represented in the coupled general circulation models (CGCMs of the Coupled Model Intercomparison Project phase 3 (CMIP3. In this study, 18 models from CMIP5 projects are evaluated in simulating the annual cycle in the EEP. Fourteen models are able to simulate the annual cycle, and four still show erroneous information in the simulation, which suggests that the performances of CGCMs have been improved. The results of multi-model ensemble (MME mean show that CMIP5 CGCMs can capture the annual cycle signal in the EEP with correlation coefficients up to 0.9. For amplitude simulations, EEP region 1 (EP1 near the eastern coast shows weaker results than observations due to the large warm SST bias from the southeastern tropical Pacific in the boreal autumn. In EEP region 2 (EP2 near the central equatorial Pacific, the simulated amplitudes are nearly the same as the observations because of the presence of a quasi-constant cold bias associated with poor cold tongue climatology simulation in the CGCMs. To improve CGCMs in the simulation of a realistic SST seasonal cycle, local and remote climatology SST biases that exist in both CMIP3 and CMIP5 CGCMs must be resolved at least for the simulation in the central equatorial Pacific and the southeastern tropical Pacific.

To study the variation characteristics of SST in coastal south China, observed SST was analyzed for the past 44 years. The results show that the monthly and yearly averaged SST have rising trends, the yearly averaged SST's linearity rising rate is 0.12-0.19 ℃/decade in the years, the rising extents in winter are higher than those in summer. The variability in winter is larger than that in summer, with the largest in February and March. A majority of significant cold or warm events occurred in winter. A wavelet multiresolution method was used to analyze periodical characteristics of SST in coastal south China, all timescale decomposition series are very similar, and high-frequency decompositions within the year are dominant. Low-frequency decompositions show rising trends since the mid-1970.

a complex phenomena, as it is influenced by several coupled ocean atmospheric phenomena such as ElNino, ElNino Modki, Indian Ocean Dipole and Madden Julian Oscillation. . Keywords Indian Ocean, tropical cyclones, cyclogenesis parameter... humidity over the Bay of Bengal during the period 1951‐2007 and the atmospheric parameters such as low‐level vorticity, mid‐tropospheric humidity and vertical wind shear, all play an important role in the genesis and intensification of storms over this basin. Air‐sea interaction processes like...

During the winter of 2015, there was a strong El Nino (ENSO) event, resulting in significant anomalies for meteorological conditions in China. Analysis shows that the meteorological conditions in December 2015 (compared to December 2014) had several important anomalies, including the following: (1) the surface southeasterly winds were significantly enhanced in the North China Plain (NCP); (2) the precipitation was increased in the south of eastern China; and (3) the wind speeds were decreased in the middle-north of eastern China, while slightly increased in the south of eastern China. These meteorological anomalies produced important impacts on the aerosol pollution in eastern China. In the NCP region, the PM2.5 concentrations were significantly increased, with a maximum increase of 80–100 μg m−3. A global chemical/transport model (MOZART-4) was applied to study the individual contribution of the changes in winds and precipitation to PM2.5 concentrations. This study suggests that the 2015El Nino event had significant effects on air pollution in eastern China, especially in the NCP region, including the capital city of Beijing, in which aerosol pollution was significantly enhanced in the already heavily polluted capital city of China. PMID:27671839

Emissions from landscape fires affect both climate and air quality. Here, we combine satellite-derived fire estimates and atmospheric modelling to quantify health effects from fire emissions in southeast Asia from 1997 to 2006. This region has large interannual variability in fire activity owing to coupling between El Nino-induced droughts and anthropogenic land-use change. We show that during strong El Nino years, fires contribute up to 200 micrograms per cubic meter and 50 ppb in annual average fine particulate matter (PM2.5) and ozone surface concentrations near fire sources, respectively. This corresponds to a fire contribution of 200 additional days per year that exceed the World Health Organization 50 micrograms per cubic metre 24-hr PM(sub 2.5) interim target and an estimated 10,800 (6,800-14,300)-person (approximately 2 percent) annual increase in regional adult cardiovascular mortality. Our results indicate that reducing regional deforestation and degradation fires would improve public health along with widely established benefits from reducing carbon emissions, preserving biodiversity and maintaining ecosystem services.

During the winter of 2015, there was a strong El Nino (ENSO) event, resulting in significant anomalies for meteorological conditions in China. Analysis shows that the meteorological conditions in December 2015 (compared to December 2014) had several important anomalies, including the following: (1) the surface southeasterly winds were significantly enhanced in the North China Plain (NCP); (2) the precipitation was increased in the south of eastern China; and (3) the wind speeds were decreased in the middle-north of eastern China, while slightly increased in the south of eastern China. These meteorological anomalies produced important impacts on the aerosol pollution in eastern China. In the NCP region, the PM2.5 concentrations were significantly increased, with a maximum increase of 80-100 μg m(-3). A global chemical/transport model (MOZART-4) was applied to study the individual contribution of the changes in winds and precipitation to PM2.5 concentrations. This study suggests that the 2015El Nino event had significant effects on air pollution in eastern China, especially in the NCP region, including the capital city of Beijing, in which aerosol pollution was significantly enhanced in the already heavily polluted capital city of China.

The monitoring and prediction of climate-induced variations in crop yields, production and export prices in major food-producing regions have become important to enable national governments in import-dependent countries to ensure supplies of affordable food for consumers. Although the El Nino/Southern Oscillation (ENSO) often affects seasonal temperature and precipitation, and thus crop yields in many regions, the overall impacts of ENSO on global yields are uncertain. Here we present a global map of the impacts of ENSO on the yields of major crops and quantify its impacts on their global-mean yield anomalies. Results show that El Nino likely improves the global-mean soybean yield by 2.15.4 but appears to change the yields of maize, rice and wheat by -4.3 to +0.8. The global-mean yields of all four crops during La Nina years tend to be below normal (-4.5 to 0.0).Our findings highlight the importance of ENSO to global crop production.

During the winter of 2015, there was a strong El Nino (ENSO) event, resulting in significant anomalies for meteorological conditions in China. Analysis shows that the meteorological conditions in December 2015 (compared to December 2014) had several important anomalies, including the following: (1) the surface southeasterly winds were significantly enhanced in the North China Plain (NCP); (2) the precipitation was increased in the south of eastern China; and (3) the wind speeds were decreased in the middle-north of eastern China, while slightly increased in the south of eastern China. These meteorological anomalies produced important impacts on the aerosol pollution in eastern China. In the NCP region, the PM2.5 concentrations were significantly increased, with a maximum increase of 80–100 μg m‑3. A global chemical/transport model (MOZART-4) was applied to study the individual contribution of the changes in winds and precipitation to PM2.5 concentrations. This study suggests that the 2015El Nino event had significant effects on air pollution in eastern China, especially in the NCP region, including the capital city of Beijing, in which aerosol pollution was significantly enhanced in the already heavily polluted capital city of China.

Tropical Atlantic SST shows a (statistically well-defined) decadal time scale in a 104-year simulation of unforced variability by a coupled general circulation model (CGCM). The SST anomalies superficially resemble observed Tropical Atlantic variability (TAV), and are associated with changes in the atmospheric circulation. Brazilian rainfall is modulated with a decadal time scale, along with the strength of the Atlantic trade winds, which are associated with variations in evaporation and the net surface heat flux. However, in contrast to observed tropical Atlantic variability, the trade winds damp the associated anomalies in ocean temperature, indicating a negative feedback. Tropical SST anomalies in the CGCM, though opposed by the surface heat flux, are advected in from the Southern Hemisphere mid-latitudes. These variations modulate the strength of the thermohaline circulation (THC): warm, salty anomalies at the equator sink drawing cold, fresh mid-latitude water. Upon reaching the equator, the latter inhibit vertical overturning and advection from higher latitudes, which allows warm, salty anomalies to reform, returning the cycle to its original state. Thus, the cycle results from advection of density anomalies and the effect of these anomalies upon the rate of vertical overturning and surface advection. This decadal modulation of Tropical Atlantic SST and the thermohaline circulation is correlated with ocean heat transport to the Northern Hemisphere high latitudes and Norwegian Sea SST. Because of the central role of equatorial convection, we question whether this mechanism is present in the current climate, although we speculate that it may have operated in palaeo times, depending upon the stability of the tropical water column.

The ASTRI SST-2M telescope is an end-to-end prototype proposed for the Small Size class of Telescopes (SST) of the future Cherenkov Telescope Array (CTA). The prototype is installed in Italy at the INAF observing station located at Serra La Nave on Mount Etna (Sicily) and it was inaugurated in September 2014. This paper presents the software and hardware architecture and development of the system dedicated to the control of the mount, health, safety and monitoring systems of the ASTRI SST-2M telescope prototype. The mount control system installed on the ASTRI SST-2M telescope prototype makes use of standard and widely deployed industrial hardware and software. State of the art of the control and automation industries was selected in order to fulfill the mount related functional and safety requirements with assembly compactness, high reliability, and reduced maintenance. The software package was implemented with the Beckhoff TwinCAT version 3 environment for the software Programmable Logical Controller (PLC), while the control electronics have been chosen in order to maximize the homogeneity and the real time performance of the system. The integration with the high level controller (Telescope Control System) has been carried out by choosing the open platform communications Unified Architecture (UA) protocol, supporting rich data model while offering compatibility with the PLC platform. In this contribution we show how the ASTRI approach for the design and implementation of the mount control system has made the ASTRI SST-2M prototype a standalone intelligent machine, able to fulfill requirements and easy to be integrated in an array configuration such as the future ASTRI mini-array proposed to be installed at the southern site of the Cherenkov Telescope Array (CTA).

Snow-water equivalent (SWE) data measured at several hundred montane sites in the western United States are used to examine the historic effects of El Nino and La Nina events on seasonal snowpack evolution in the major subbasins in the Columbia and Colorado River systems. Results are used to predict annual runoff. In the Columbia River Basin, there is a general tendency for decreased SWE during El Nino years and increased SWE in La Nina years. However, the SWE anomalies for El Nino years are much less pronounced. This occurs in part because midlatitude circulation anomalies in El Nino years are located 35?? east of those in La Nina years. This eastward shift is most evident in midwinter, at which time, SWE anomalies associated with El Nino are actually positive in coastal regions of the Columbia River Basin. In the Colorado River Basin, mean anomalies in SWE and annual runoff during El Nino years depict a transition between drier-than-average conditions in the north, and wetter-than-average conditions in the southwest. Associations during La Nina years are generally opposite those in El Nino years. SWE anomalies tend to be more pronounced in spring in the Lower Colorado River Basin. Our predictions of runoff reveal modest skill for scenarios using only historic El Nino and La Nina information. Predictions based on the water stored in the seasonal snowpack are, in almost all cases, much higher than those based on El Nino-Southern Oscillation (ENSO) information alone. However, combining observed midwinter snow conditions with information on seasonal snowpack evolution associated with ENSO improves predictions for basins in which ENSO signals exhibit strong seasonality.

Heavy rainfall associated with a strong El Nino caused over $150 million in landslide damage in the 10-county San Francisco Bay region during the winter and spring of 1998. A team of USGS scientists collected information on landslide locations and damage costs. About $27 million in damages were assessed in Contra Costa County.

Heavy rainfall associated with a strong El Nino caused over $150 million in landslide damage in the 10-county San Francisco Bay region during the winter and spring of 1998. A team of USGS scientists collected information on landslide locations and damage costs. About $14.5 million in damages were assessed in Santa Cruz County.

Heavy rainfall associated with a strong El Nino caused over $150 million in landslide damage in the 10-county San Francisco Bay region during the winter and spring of 1998. A team of USGS scientists collected information on landslide locations and damage costs. About $21 million in damages were assessed in Sonoma County.

Heavy rainfall associated with a strong El Nino caused over $150 million in landslide damage in the 10-county San Francisco Bay region during the winter and spring of 1998. A team of USGS scientists collected information on landslide locations and damage costs. About $13.5 million in damages were assessed in Solano County.

Heavy rainfall associated with a strong El Nino caused over $150 million in landslide damage in the 10-county San Francisco Bay region during the winter and spring of 1998. A team of USGS scientists collected information on landslide locations and damage costs. About $2.5 million in damages were assessed in Marin County.

This research examines the relationships between El Nino Southern Oscillation (ENSO), water level, precipitation patterns and carbon dioxide (CO2) exchange rates in the freshwater wetland ecosystems of the Florida Everglades. Data was obtained over a 5-year study period (2009â2013) from two freshwater marsh sites located in Everglades National Park that differ...

Heavy rainfall associated with a strong El Nino caused over $150 million in landslide damage in the 10-county San Francisco Bay region during the winter and spring of 1998. A team of USGS scientists collected information on landslide locations and damage costs. About $7.6 million in damages were assessed in Santa Clara County.

Modeling globally averaged information on climate forcing from the land surface temperature data, the sea surface temperatures (SST) and the empirically determined relationship between the changes in SST and the turbulent diffusion of heat into the upper ocean demonstrates a consistent link. The modeling is accurate throughout the 20th century despite the different phases of the Interdecadal Pacific Oscillation (IPO) or the strong divergence between land and ocean surface warming. It only fails during the last 15 years when SST drops well below the trend. The finding reinforces the view that slower global warming over the previous 15 years is not a caused by a negative phase of the IPO or by the variations in the upper ocean (top 700 m) warming but results from a change in the ocean behavior leading to increased heat transfer into the deeper ocean.

The helium refrigerator/liquefier (R/L) for the Steady State Super conducting Tokamak (SST-1) has been developed with very stringent specifications for the different operational modes. The total refrigeration capacity is 650 W at 4.5 K and liquefaction capacity of 200 l/h. A cold circulation pump is used for the forced flow cooling of 300 g/s supercritical helium (SHe) for the magnet system (SCMS). The R/L has been designed also to absorb a 200 W transient heat load of the SCMS. The plant consists of a compressor station, oil removal system, on-line purifier, Main Control Dewar (MCD) with associated heat exchangers, cold circulation pump and warm gas management system. An Integrated Flow Control and Distribution System (IFDCS) has been designed, fabricated and installed for distribution of SHe in the toroidal and poloidal field coils as well as liquid helium for cooling of 10 pairs of current leads. A SCADA based control system has been designed using PLC for R/L as well as IFDCS. The R/L has been commissioned and required parameters were achieved confirming to the process. All the test results and commissioning experiences are discussed in this paper.

Highlights: • Induced EMFs study in PF coils during SST-1 start up using MATlab simulink. • Integration of wave shaping network to generate practical OT current profile. • This study would protect coil insulation with identifying RC circulating network. • Study of MOV technique for circulation of current through RC. - Abstract: Steady State Superconducting Tokamak (SST-1) comprises of various copper and superconducting coils for generating magnetic field for initiation, providing equilibrium and shaping of plasma in tokamak. In this paper, an attempt is made to study the induced EMF in superconducting poloidal field coils (PF coils) due to fast ramp down of current in ohmic transformer copper coils (OT coils) for SST-1 plasma initiation. The fast ramp down of current, from few kA to zero amperes in just 50–100 ms in OT coils, is required to achieve plasma breakdown and ramp up of plasma current in tokamak. However, it induces nearly 5 kV EMF in one of the SST-1 PF coils that can damage the coil insulation and also bias negatively the electronic switching of power supply. It is necessary to maintain induced EMF below 1 kV in all PF coils for safe operation of SST-1. The induced EMF up to 1 kV can be clamped without any need of protection and circulating current. If the induced EMF is in excess of 1 kV, then it has to allow the circulation of current through RC network for coil protection from overvoltage. These circulating currents in PF coils will affect the shaping of plasma. In this paper, the induced EMF in PF coils are simulated using MATlab simulink for a typical SST-1 current profile of OT coils. Further, this simulation study is used to design the protection system for PF coils. In this paper, the worst-case induced EMF scenario is considered by excluding the effect of passive elements like vacuum vessel and cryostat on mutual coupling parameters. However, the implementation of the EMF suppression scheme need more elaborated study with considering

Sea surface temperature (SST) changes during the Eocene-Oligocene climate transition were characterized by substantial cooling at high latitudes and less cooling in low latitudes, with little information from mid-latitudes so far. Taking advantage of the newly retrieved drift sediments from the IODP 342 Expedition, we aim to reconstruct SST changes at the mid-latitude Newfoundland region, at an unprecedented orbital resolution from Site U1411. During the period investigated, 32-36 Ma, the alkenone UK'37 values range from 0.65 to 0.95, with values all greater than 0.80 before the transition and lower values (polar waters (fronts) reached to the region occasionally at periods of eccentricity minimum nodes during the Oligocene.

Despite the same purpose, each satellite product has different value because of its inescapable uncertainty. Also the satellite products have been calculated for a long time, and the kinds of the products are various and enormous. So the efforts for reducing the uncertainty and dealing with enormous data will be necessary. In this paper, we create an ensemble Sea Surface Temperature (SST) using MODIS Aqua, MODIS Terra and COMS (Communication Ocean and Meteorological Satellite). We used Bayesian Model Averaging (BMA) as ensemble method. The principle of the BMA is synthesizing the conditional probability density function (PDF) using posterior probability as weight. The posterior probability is estimated using EM algorithm. The BMA PDF is obtained by weighted average. As the result, the ensemble SST showed the lowest RMSE and MAE, which proves the applicability of BMA for satellite data ensemble. As future work, parallel processing techniques using Hadoop framework will be adopted for more efficient computation of very big satellite data.

The single mirror Small Size Telescopes (SST-1M), being built by a sub-consortium of Polish and Swiss Institutions of the CTA Consortium, will be equipped with a fully digital camera with a compact photodetector plane based on silicon photomultipliers. The internal trigger signal transmission overhead will be kept at low level by introducing a high level of integration. It will be achieved by massively deploying state-of-the-art multi-gigabit transceivers, beginning from the ADC flash converters, through the internal data and trigger signals transmission over backplanes and cables, to the camera's server 10Gb/s Ethernet links. Such approach will allow fitting the size and weight of the camera exactly to the SST-1M needs, still retaining the flexibility of a fully digital design. Such solution has low power consumption, high reliability and long lifetime. The concept of the camera will be described, along with some construction details and performance results.

A pattern of variability in precipitation and 1000mb zonal winds for the tropical Indian Ocean during, 1979 to 1999 (AtmIO mode) is described using EOFs. The AtmIO mode consists of a cross-equatorial gradient of precipitation anomalies and equatorial wind anomalies of alternating signs on the Equator. The positive phase is defined as enhanced precipitation to the In "n south of the equator, suppressed precipitation to the north, and anomalous westerlies centered on the island of Sumatra. In September-October 1981, February-March 1990, and October-December 1996 the AtmIO mod-, was positive and there was a significant 30-60 day variability in the gradient of precipitation anomalies. These cases coincided with moderate to heavy ,activity in the Madden-Jullan Oscillation (MJO). Links between the AtmIO, MJO, and El Nino are discussed.

Most of the existing prediction methods gave a false alarm regarding the El Ni\\~no event in 2014. A crucial aspect is currently limiting the success of such predictions, i.e. the stability of the slowly varying Pacific climate. This property determines whether sea surface temperature perturbations will be amplified by coupled ocean-atmosphere feedbacks or not. The so-called Bjerknes stability index has been developed for this purpose, but its evaluation is severely constrained by data availability. Here we present a new promising background stability index based on complex network theory. This index efficiently monitors the changes in spatial correlations in the Pacific climate and can be evaluated by using only sea surface temperature data.

Information on the ocean/atmosphere state over the period spanning the Last Glacial Maximum - from the Late Pleistocene to the Holocene - provides crucial constraints on the relationship between orbital forcing and global climate change. The Pacific Ocean is particularly important in this respect because of its dominant role in exporting heat and moisture from the tropics to higher latitudes. Through targeting groundwaters in the Mojave Desert, California, we show that noble gas derived temperatures in California averaged 4.2 ?? 1.1 ??C cooler in the Late Pleistocene (from ???43 to ???12 ka) compared to the Holocene (from ???10 to ???5 ka). Furthermore, the older groundwaters contain higher concentrations of excess air (entrained air bubbles) and have elevated oxygen-18/oxygen-16 ratios (??18O) - indicators of vigorous aquifer recharge, and greater rainfall amounts and/or more intense precipitation events, respectively. Together, these paleoclimate indicators reveal that cooler and wetter conditions prevailed in the Mojave Desert from ???43 to ???12 ka. We suggest that during the Late Pleistocene, the Pacific ocean/atmosphere state was similar to present-day El Nino-like patterns, and was characterized by prolonged periods of weak trade winds, weak upwelling along the eastern Pacific margin, and increased precipitation in the southwestern U.S.

A new, simple conceptual model of surface specific humidity change (∆q) over land has been developed, based on the effect of increased moisture advection from the oceans in response to sea surface temperature (SST) warming. In this model, future q over land is determined by scaling the present-day pattern of land q by the fractional increase in the oceanic moisture source. Simple model estimates agree well with climate model projections of future ∆q (mean spatial correlation coefficient 0.87), so ∆q over both land and ocean can be viewed primarily as a thermodynamic process controlled by SST warming. Precipitation change (∆P) is also affected by ∆q, and the new simple model can be included in a decomposition of tropical precipitation change, where it provides increased physical understanding of the processes that drive ∆P over land. Confidence in the thermodynamic part of extreme precipitation change over land is increased by this improved understanding, and this should scale approximately with Clausius-Clapeyron oceanic q increases under SST warming. Residuals between actual climate model ∆q and simple model estimates are often associated with regions of large circulation change, and can be thought of as the 'dynamical' part of specific humidity change. The simple model is used to explore inter-model uncertainty in ∆q, and there are substantial contributions to uncertainty from both the thermodynamic (simple model) and 'dynamical' (residual) terms. The largest cause of inter-model uncertainty within the thermodynamic term is uncertainty in the magnitude of global mean SST warming.

The validity of scale model impact evaluation of the SST Transportation System is acceptable based on Dimensional Analysis (Buckingham Pi Theorem) and the work of numerous programs that have evaluated the agreement among dimensional analysis, several different reduced-size models and full-scale impact test data. Excellent accuracy has been demonstrated between scale models and full-scale impact data when collected in conformance with the Buckingham Pi Theorem. 20 refs., 4 figs.

This paper describes the variability in the diurnal range of SST in the north Indian Ocean using in situ measurements and tests the suitability of simple regression models in estimating the diurnal range.SST measurements obtained from 1556 drifting and 25 moored buoys were used to determine the diurnal range of SSTs.The magnitude of diurnal range of SST was highest in spring and lowest in summer monsoon.Except in spring,nearly 75 –80%of the observations reported diurnal range below 0.5°C.The distributions of the magnitudes of diurnal warming across the three basins of north Indian Ocean (Arabian Sea,Bay of Bengal and Equatorial Indian Ocean)were similar except for the differences between the Arabian Sea and the other two basins during November-February (winter monsoon)and May.The magnitude of diurnal warming that depended on the location of temperature sensor below the water level varied with seasons.In spring,the magnitude of diurnal warming diminished drastically with the increase in the depth of temperature sensor.The diurnal range estimated using the drifting buoy data was higher than the diurnal range estimated using moored buoys ﬁtted with temperature sensors at greater depths. A simple regression model based on the peak solar radiation and average wind speed was good enough to estimate the diurnal range of SST at ∼1.0 m in the north Indian Ocean during most of the seasons except under low wind-high solar radiation conditions that occur mostly during spring. The additional information on the rate of precipitation is found to be redundant for the estimation of the magnitude of diurnal warming at those depths.

Over the last decade there have been commercial TOF-PET scanners constructed using Photo-Multiplier Tubes (PMT) that have achieved ∼500ps FWHM Coincidence Time Resolution (CTR). A new device known as the Silicon PhotoMultiplier (SiPM) has the potential to overcome some of the limitations of the PMT. Therefore implementing a SiPM based TOF-PET scanner is of high interest. Recently Philips has introduced a TOF-PET scanner that uses digital Silicon PhotoMultipliers (d-SiPMs) which has a CTR of 350 ps. Here we will report on the timing performance of two Hamamatsu 3×3 mm{sup 2} analogue-SiPMs read out with the NINO ASIC: this is an ultra-fast amplifier/discriminator with a differential architecture. The differential architecture is very important since the single-ended readout uses the ground as the signal return; as the ground is also the reference level for the discriminators, the result is high crosstalk and degraded time resolution. However differential readout allows the scaling up from a single cell to a multi-cell device with no loss of time resolution; this becomes increasingly important for the highly segmented detectors that are being built today, both for particle and for medical instrumentation. We obtained excellent results for both the Single Photon Time Resolution (SPTR) and for the CTR using a LYSO crystal of 15 mm length. Such a crystal length has sufficient detection efficiency for 511 keV gammas to make an excellent PET device. The results presented here are proof that a TOF-PET detector with a CTR of 175 ps is indeed possible. This is the first step that defines the starting point of our SuperNINO project.

Full Text Available The paper discusses the modeling and prediction of the climate of our planet with the use of artificial intelligence AIDOS-X. We have developed a number of semantic information models, demonstrating the presence of the elements of similarity between the motion of the lunar orbit and the displacement of the instantaneous pole of the Earth. It was found that the movement of the poles of the Earth leading to the variations in the magnetic field, seismic events, as well as violations of the global atmospheric circulation and water, and particular to the emergence of episodes such as El Niño and La Niña. Through semantic information models studied some equatorial regions of the Pacific Ocean, as well as spatial patterns of temperate latitudes, revealed their relative importance for the prediction of global climatic disturbances in the tropical and temperate latitudes. The reasons of occurrence of El Niño Modoki and their relationship with the movement of elements of the lunar orbit in the long-term cycles are established. Earlier, we had made a forecast of the occurrence of El Niño episode in 2015. Based on the analysis of semantic models concluded that the expected El Niño classical type. On the basis of the prediction block AIDOS-X calculated monthly evolution scenario of global climate anomalies. In this paper, the analysis of the actual implementation forecast of El Niño since its publication in January 2015 - before June 2015. It is shown that the predicted scenario of climatic anomalies actually realized. Calculations of future climate scenarios with system «Aidos-X» recognition module indicate that further possible abnormal excess temperature indicators of surface ocean waters in regions Nino 1,2 and Nino3,4 for 2015 may be comparable with similar abnormalities in the catastrophic El Niño of 1997-1998.

Recent advances in our understanding of the dynamics in the upper layers of the ocean have allowed us to develop methodologies to recover high resolution velocities from surface measurements such as Sea Surface Heights (SSH) and Sea Surface Temperatures (SST). These methods are based on the combined use of advanced signal processing techniques, such as wavelet analysis and singularity analysis, with dynamical approaches such as the Surface Quasi-Geostrophic (SQG) equations. Within the SQG framework, SSH and SST are closely related, which can be exploited to develop a synergetic approach that combines existing satellite measurements of these fields that can be used to recover subsurface buoyancy anomaly, surface and subsurface horizontal velocities and vertical velocities in the upper 300-500 m. Sentinel-3 satellite will follow its predecessors, ERS-1/2 and Envisat, and will provide simultaneous measurements of SST (SLSTR instrument) and SSH (SRAL and auxiliary instruments) that can be combined to produce high resolution surface currents. To test the feasibility of this approach for Sentinel-3 satellites we have reconstructed surface currents from AATSR and RA data provided by Envisat and compared results against independent SSH measurements provided Jason-1/2 platforms.

ASTRI SST-2M is an end-to-end telescope prototype developed by the Italian National Institute of Astrophysics (INAF) in the framework of the Cherenkov Telescope Array (CTA). The CTA observatory, with a combination of large-, medium-, and small-sized telescopes (LST, MST and SST, respectively), will represent the next generation of imaging atmospheric Cherenkov telescopes. It will explore the very high-energy domain from a few tens of GeV up to few hundreds of TeV. The ASTRI SST-2M telescope structure and mirrors have been installed at the INAF observing station at Serra La Nave, on Mt. Etna (Sicily, Italy) in September 2014. Its performance verification phase began in autumn 2015. Part of the scheduled activities foresees the study and characterization of the optical and opto-mechanical performance of the telescope prototype. In this contribution we report the results achieved in terms of kinematic model analysis, mirrors reflectivity evolution, telescopes positioning, flexures and pointing model and the thermal behavior.

The turbulent air-sea heat flux feedback (α, in {W m}^{-2} { K}^{-1}) is a major contributor to setting the damping timescale of sea surface temperature (SST) anomalies. In this study we compare the spatial distribution and magnitude of α in the North Atlantic and the Southern Ocean, as estimated from the ERA-Interim reanalysis dataset. The comparison is rationalized in terms of an upper bound on the heat flux feedback, associated with "fast" atmospheric export of temperature and moisture anomalies away from the marine boundary layer, and a lower bound associated with "slow" export. It is found that regions of cold surface waters (≤10 ° C) are best described as approaching the slow export limit. This conclusion is not only valid at the synoptic scale resolved by the reanalysis data, but also on basin scales. In particular, it applies to the heat flux feedback acting as circumpolar SST anomaly scales are approached in the Southern Ocean, with feedbacks of ≤10 {W m}^{-2} { K}^{-1}. In contrast, the magnitude of the heat flux feedback is close to that expected from the fast export limit over the Gulf Stream and its recirculation with values on the order of ≈40 {W m}^{-2} { K}^{-1}. Further analysis suggests that this high value reflects a compensation between a moderate thermodynamic adjustment of the boundary layer, which tends to weaken the heat flux feedback, and an enhancement of the surface winds over warm SST anomalies, which tend to enhance the feedback.

The turbulent air-sea heat flux feedback (α , in {W m}^{-2}{ K}^{-1} ) is a major contributor to setting the damping timescale of sea surface temperature (SST) anomalies. In this study we compare the spatial distribution and magnitude of α in the North Atlantic and the Southern Ocean, as estimated from the ERA-Interim reanalysis dataset. The comparison is rationalized in terms of an upper bound on the heat flux feedback, associated with "fast" atmospheric export of temperature and moisture anomalies away from the marine boundary layer, and a lower bound associated with "slow" export. It is found that regions of cold surface waters (≤ 10° C) are best described as approaching the slow export limit. This conclusion is not only valid at the synoptic scale resolved by the reanalysis data, but also on basin scales. In particular, it applies to the heat flux feedback acting as circumpolar SST anomaly scales are approached in the Southern Ocean, with feedbacks of ≤ 10 {W m}^{-2}{ K}^{-1} . In contrast, the magnitude of the heat flux feedback is close to that expected from the fast export limit over the Gulf Stream and its recirculation with values on the order of ≈40 {W m}^{-2}{ K}^{-1} . Further analysis suggests that this high value reflects a compensation between a moderate thermodynamic adjustment of the boundary layer, which tends to weaken the heat flux feedback, and an enhancement of the surface winds over warm SST anomalies, which tend to enhance the feedback.

The effects of storm-induced sea surface temperature (SST) cooling on hurricane intensity are investigated using a 5-day cloud-resolving simulation of Hurricane Bonnie (1998). Two sensitivity simulations are performed in which the storm-induced cooling is either ignored or shifted close to the modeled storm track. Results show marked sensitivity of the model-simulated storm intensity to the magnitude and relative position with respect to the hurricane track. It is shown that incorporation of the storm-induced cooling, with an average value of 1.3℃, causes a 25-hPa weakening of the hurricane, which is about 20hPa per 1℃ change in SST. Shifting the SST cooling close to the storm track generates the weakest storm,accounting for about 47% reduction in the storm intensity. It is found that the storm intensity changes are well correlated with the air-sea temperature difference. The results have important implications for the use of coupled hurricane-ocean models for numerical prediction of tropical cyclones.

In 2014 the ASTRI Collaboration, led by the Italian National Institute for Astrophysics, has constructed an end-to-end prototype of a dual-mirror imaging air Cherenkov telescope, proposed for the small size class of telescopes for the Cherenkov Telescope Array. The prototype, named ASTRI SST-2M, has been installed at the observing station located at Serra La Nave (Italy). In this project the Brera Astronomical Observatory was responsible for the production and the testing of the primary mirror. The ASTRI SST-2M telescope's primary mirror has an aperture of ~ 4 m, a polynomial design, and consists of 18 individual hexagonal facets. These characteristics require the production and testing of panels with a typical size of ~1 m vertex-to-vertex and with an aspheric component of up to several millimetres. The mirror segments were produced assembling a sandwich of thin glass foils bent at room temperature to reach the desired shape. For the characterization of the mirrors we developed an ad-hoc deflectometry facility that works as an inverse Ronchi test in combination with a ray-tracing code. In this contribution we report the results of the deflectometric measurements performed on the primary mirror segments of the ASTRI SST-2M dual mirror telescope. The expected point spread function and the contributions to the degradation of the image quality are studied.

ASTRI is a Flagship Project led by the Italian National Institute of Astrophysics, INAF. The main objective of the ASTRI project is to develop a prototype of the Small Size class Telescope for the Cherenkov Telescope Array (CTA) in a dual-mirror configuration (SST-2M). The ASTRI SST-2M is an end-to-end prototype that will be fully developed by the ASTRI Collaboration from the optics design and manufacturing to the focal plane camera, from the structure of the mount to all the needed software. The ASTRI SST-2M prototype will be placed at the INAF "M.G. Fracastoro" observing station in Serra La Nave on the Etna Mountain near Catania, Italy. The technological solutions adopted will be tested on field: observations of the Crab Nebula and of other sources will be essential part of the science verification phase, with the aim to assess the achievement of the scientific requirements. In the following we present the Serra La Nave site together with all the auxiliary instruments needed for atmospheric monitoring and c...

Spatial and temporal distribution characteristics and scale range of two significant areas were obtained by analyzing the relationship among summer rainfall in Yunnan province, height field and SST field (40°S - 40°N, 30 °E - 70°W) across the North Hemisphere at 200 hPa, 500 hPa and 850 hPa for Jan. to May and correlation, and field wave structure. Remote key regions among summer rainfall in Yunnan province, height field and SST field (40°S - 40°N, 30°E - 70°W) across the North Hemisphere at 200 hPa, 500 hPa and 850 hPa were studied through further analyzing of the circulation system and its climate / weather significance. The result shows that the forecast has dependable physical basis when height and SST fields were viewed as predictors and physical models of impacts on rainy season precipitation in Yunnan are preliminarily concluded.

The Swedish 1-m Solar Telescope (SST) offers excellent imaging quality, but it has a comparatively small field of view. This means that while observing the solar photosphere, there has been no convenient way of calibrating the image scale of the telescope. Other telescopes, such as NASA's Solar Dynamics Observatory (SDO)utilize their larger Field of View (FOV) to use the solar disk as a reference in order to measure the image scale. In the past, the image scale of the SST has been determined by measuring the distance between the moons of Jupiter in a captured SST image and comparing it to reference values, as well as with the Venus transit of 2004. Both of these methods have their drawbacks, including needing to open the telescope at night or waiting for the very rare occurrence of a solar transit, which the telescope may not even be in a position to observe. Additionally, assessing the accuracy of these methods can be difficult. The purpose of this thesis is to examine the feasibility of an idea proposed by ...

Steady State Superconducting Tokamak-1 (SST-1) at Institute for Plasma Research (IPR), India is now in engineering validation phase. The assembled Toroidal Field (TF) magnet system of SST-1 will be operated at 10 kA of nominal current at helium cooled condition of 4.5 K. A reliable and fail proof quench detection (QD) system is essential for the safety and the investment protection requirements of the magnets. This QD system needs to continuously monitor all the superconducting coils, which include 16 TF magnets, return-loop, bus bars and current leads. In case of any event initiating the normal resistive zone and reaching thermal run-away, the QD system needs to trigger the magnet protection circuits. Precision instrumentation and control system with 204 signal channels had been developed for detection of quench anywhere in the entire TF magnet system. In the present configuration of quench detection scheme, the voltage drop across each double pancake (DP) of each TF coil are compared with its two adjacent DPs for the detection of normal zone and cancelation of inductive couples. Two identical redundant systems with one out of two configurations are successfully commissioned and tested at IPR. This paper describes the design and implementation of the QD system, Installation experience, validation test and initial results from the recent SST-1 magnet system charging.

In SST-1, successful plasma startup has been achieved at very low loop voltage with the help of ECRH pre-ionization. ECRH is operated in both O mode and X mode for the purpose of pre-ionization at the pre fill pressure of 1 × 10{sup −5} mbar. A delay in breakdown has been observed in case of second harmonic ECRH pre-ionization; where in case of fundamental mode of ECRH pre-ionization, the instant breakdown has been observed. This work has attempted at explaining the non-linear interaction of the seed electrons with the electromagnetic field of the incident ECRH wave that has led to break down of the plasma. The delay in the break down attributes to the time differential between the applications of the ECRH pulse to that of the appearance of the H-alpha signal in SST-1. The observed experimental results have been discussed in this paper from the first principles and numerically solving the electron-ECRH field interactions resulting in energy gains of the electrons leading to plasma break down in SST-1 specific discharge conditions.

Purpose Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rare and heterogeneous tumors, and their biological behavior is not well known. We studied the presence and potential functional roles of somatostatin receptors (sst1-5), focusing particularly on the truncated variants (sst5TMD4, sst5TMD5) and on their relationships with the angiogenic system (Ang/Tie-2 and VEGF) in human GEP-NETs. Experimental Design We evaluated 42 tumor tissue samples (26 primary/16 metastatic) from 26 patients with GEP-NETs, and 30 non-tumoral tissues (26 from adjacent non-tumor regions and 4 from normal controls) from a single center. Expression of sst1-5, sst5TMD4, sst5TMD5, Ang1-2, Tie-2 and VEGF was analyzed using real-time qPCR, immunofluorescence and immunohistochemistry. Expression levels were associated with tumor characteristics and clinical outcomes. Functional role of sst5TMD4 was analyzed in GEP-NET cell lines. Results sst1 exhibited the highest expression in GEP-NET, whilst sst2 was the most frequently observed sst-subtype (90.2%). Expression levels of sst1, sst2, sst3, sst5TMD4, and sst5TMD5 were significantly higher in tumor tissues compared to their adjacent non-tumoral tissue. Lymph-node metastases expressed higher levels of sst5TMD4 than in its corresponding primary tumor tissue. sst5TMD4 was also significantly higher in intestinal tumor tissues from patients with residual disease of intestinal origin compared to those with non-residual disease. Functional assays demonstrated that the presence of sst5TMD4 was associated to enhanced malignant features in GEP-NET cells. Angiogenic markers correlated positively with sst5TMD4, which was confirmed by immunohistochemical/fluorescence studies. Conclusions sst5TMD4 is overexpressed in GEP-NETs and is associated to enhanced aggressiveness, suggesting its potential value as biomarker and target in GEP-NETs. PMID:26673010

National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature (SST) analysis produced daily on an operational basis by the...

Full Text Available The primary measure of the quality of sea surface temperature (SST fields obtained from satellite-borne infrared sensors has been the bias and variance of matchups with co-located in-situ values. Because such matchups tend to be widely separated, these bias and variance estimates are not necessarily a good measure of small scale (several pixels gradients in these fields because one of the primary contributors to the uncertainty in satellite retrievals is atmospheric contamination, which tends to have large spatial scales compared with the pixel separation of infrared sensors. Hence, there is not a good measure to use in selecting SST fields appropriate for the study of submesoscale processes and, in particular, of processes associated with near-surface fronts, both of which have recently seen a rapid increase in interest. In this study, two methods are examined to address this problem, one based on spectra of the SST data and the other on their variograms. To evaluate the methods, instrument noise was estimated in Level-2 Visible-Infrared Imager-Radiometer Suite (VIIRS and Advanced Very High Resolution Radiometer (AVHRR SST fields of the Sargasso Sea. The two methods provided very nearly identical results for AVHRR: along-scan values of approximately 0.18 K for both day and night and along-track values of 0.21 K for day and night. By contrast, the instrument noise estimated for VIIRS varied by method, scan geometry and day-night. Specifically, daytime, along-scan (along-track, spectral estimates were found to be approximately 0.05 K (0.08 K and the corresponding nighttime values of 0.02 K (0.03 K. Daytime estimates based on the variogram were found to be 0.08 K (0.10 K with the corresponding nighttime values of 0.04 K (0.06 K. Taken together, AVHRR instrument noise is significantly larger than VIIRS instrument noise, along-track noise is larger than along-scan noise and daytime levels are higher than nighttime levels. Given the similarity of

The present paper selects the northern winter of December 1995-February 1996 for a case study on the impact of sea surface temperature (SST) anomalies on the atmospheric circulation over the North Atlantic and Western Europe. In the Atlantic, the selected winter was characterized by positive SST anomalies over the northern subtropics and east of Newfoundland, and negative anomalies along the US coast. A weak La Nina event developed in the Pacific. The North Atlantic Oscillation (NAO) index was low, precipitation over the Iberian Peninsula and northern Africa was anomalously high, and precipitation over northern Europe was anomalously low. The method of study consists of assessing the sensitivity of ensemble simulations by the UCLA atmospheric general circulation model (UCLA AGCM) to SST anomalies from the observation, which are prescribed either in the World Oceans, the Atlantic Ocean only, or the subtropical North Atlantic only. The results obtained are compared with a control run that uses global, time-varying climatological SST. The ensemble simulations with global and Atlantic-only SST anomalies both produce results that resemble the observations over the North Atlantic and Western Europe. It is suggested that the anomalous behavior of the atmosphere in the selected winter over those regions, therefore, was primarily determined by conditions within the Atlantic basin. The simulated fields in the tropical North Atlantic show anomalous upward motion and lower (upper) level convergence (divergence) in the atmosphere overlying the positive SST anomalies. Consistently, the subtropical jet intensifies and its core moves equatorward, and precipitation increases over northern Africa and southern Europe. The results also suggest that the SST anomalies in the tropical North Atlantic only do not suffice to produce the atmospheric anomalies observed in the basin during the selected winter. The extratropical SST anomalies would provide a key contribution through increased

In order to test the sensitivity of the transitional phase of the 2006 West African monsoon (WAM) onset to different mechanisms, weather research and forecasting (WRF) model simulations have been carried out addressing the role of the Saharan heat low (SHL) and its sensitivity to the albedo field and to the northern Africa orography, and the role of the sea surface temperature (SST) in the eastern tropical Atlantic and Mediterranean. Lowering albedo over the desert region induces a northward location of the inter-tropical convergence zone (ITCZ), while removing mountains in North Africa reduces rainfall over West Africa. Shifting SST forward by 15 days leads to a northward location of the ITCZ before the WAM onset. However none of these factors modifies the timing of the WAM onset in 2006. The transitional phase of the 2006 WAM onset has been examined in more detail. The enhancement of SHL intensity, combined with the development of the oceanic cold tongue in the Guinea gulf, leads to low-level moisture flux divergence in the ITCZ reducing rainfall and increasing low-level humidity over the Sahel. However, weakening of convection can be clearly attributed to dry-air intrusions in mid-levels, originating from the subtropical westerly jet and associated with Rossby wave pattern over North Africa. Sensitivity tests on the synoptic scale forcing outside of the WRF model domain confirm the dominating role of large-scale dynamics to control the transitional phase of the WAM onset and its timing. However it is shown that the regional factors can modulate this larger scale forcing. (orig.)

This work presents an analysis of the ELETRONORTE hydrothermal systems in the States of Amazonas, Rondonia and Amapa and the Tucurui HPP Interconnected System. The analysis ranges from the whole year of 1997 to September 1998, considering the strong influence of the El Nino phenomenon, initiated on April 1997, on the flows affluent to the reservoirs of Balbina, Samuel, Coaracy Nunes and Tucurui Hydroelectric Power Plants.

The interannual variations of atmospheric heat sources and moisture sinks over the Equatorial Pacific and their relations with the SST anomalies are studied using ECMWF reanalysis data from 1979 to 1993. It is found by singular value decomposition (SVD) analysis that the region in the tropical Pacific with high positive correlation between the vertically integrated heat source anomaly and the SST anomaly, and between the vertically integrated moisture sink anomaly and the SST anomaly, is mainly located in a long and narrow belt to the east of 170 (E between 5 (S and 5 (N. The analysis of the vertical structure of atmospheric heat sources and moisture sinks shows that the interannual variations of Q1, Q2 and SST in the equatorial central and eastern Pacific are strongly and positively correlated in the whole troposphere except the bottom (962.5 hPa) and the top (85 hPa) layers. However, in the western Pacific, the interannual variations of Q1 below 850 hPa is negatively related to the SST. The correlation coefficient at the level 962.5 hPa reaches even -0.59. In other layers the positive correlation between the interannual variations of Q1, Q2 and the SST are weak in the western Pacific.

Multichannel regression algorithms are widely used to retrieve sea surface temperature (SST) from infrared observations with satellite radiometers. Their theoretical foundations were laid in the 1980s-1990s, during the era of the Advanced Very High Resolution Radiometers which have been flown onboard NOAA satellites since 1981. Consequently, the multi-channel and non-linear SST algorithms employ the bands centered at 3.7, 11 and 12 μm, similar to available in AVHRR. More recent radiometers carry new bands located in the windows near 4 μm, 8.5 μm and 10 μm, which may also be used for SST. Involving these bands in SST retrieval requires modifications to the regression SST equations. The paper describes a general approach to constructing SST regression equations for an arbitrary number of radiometric bands and explores the benefits of using extended sets of bands available with the Visible Infrared Imager Radiometer Suite (VIIRS) flown onboard the Suomi National Polar-orbiting Partnership (SNPP) and to be flown onboard the follow-on Joint Polar Satellite System (JPSS) satellites, J1-J4, to be launched from 2017-2031; Moderate Resolution Imaging Spectroradiometers (MODIS) flown onboard Aqua and Terra satellites; and the Advanced Himawari Imager (AHI) flown onboard the Japanese Himawari-8 satellite (which in turn is a close proxy of the Advanced Baseline Imager (ABI) to be flown onboard the future Geostationary Operational Environmental Satellites - R Series (GOES-R) planned for launch in October 2016.

The design and performance of a fully-synchronous multi-GHz analog transient waveform recorder I.C. ("SST") with fast and flexible trigger capabilities is presented. The SST's objective is to provide multi-GHz sample rates with intrinsically-stable timing, Nyquist-rate sampling and high trigger bandwidth, wide dynamic range and simple operation. Containing 4 channels of 256 samples per channel, the SST is fabricated in an inexpensive 0.25 micrometer CMOS process and uses a high-performance package that is 8 mm on a side. It has a 1.9V input range on a 2.5V supply, exceeds 12 bits of dynamic range, and uses ~128 mW while operating at 2 G-samples/s and full trigger rates. With a standard 50 Ohm input source, the SST exceeds ~1.5 GHz -3 dB bandwidth. The SST's internal sample clocks are generated synchronously via a shift register driven by an external LVDS oscillator running at half the sample rate (e.g., a 1 GHz oscillator yields 2 G-samples/s). Because of its purely-digital synchronous nature, the SST has ps-...

An eigen analysis of the equatorial air-sea coupled model is carried out to understand the mechanism of the slowly varying mode for various zonal phase differences between SST and wind stress. The frequency and growth rate of the slow mode highly depend on the zonal phase difference between SST and wind stress anomalies and the wave scale. For ultra-long waves longer than 20,000 km, the system propagates westward regardless of the position of wind stress. However, for the long waves observed in the Pacific, the slow mode tends to propagate eastward when the SST and wind stress anomalies are close to each other (within a quadrature phase relationship). On the other hand, when the wind stress is located far away from SST, the slow mode tends to propagate westward. The coupled system produces the unstable modes when the westerly (easterly) wind stress is located in the west of warm (cold) SST. It is noted that for the Pacific basin scale,the eastward propagating unstable waves can be produced when the wind stress is located to the west of SST with a few thousand kilometer distance. Also examined in the present study is the relative role of the thermocline displacement and zonal advection effects in determining the propagation and instability of the coupled system.

Somatostatin receptors (SSTRs) are proposed to mediate the actions of somatostatin (SST) and its related peptide, cortistatin (CST), in vertebrates. However, the identity, functionality, and tissue expression of these receptors remain largely unknown in most non-mammalian vertebrates including birds. In this study, five SSTRs (named cSSTR1, cSSTR2, cSSTR3, cSSTR4, cSSTR5) were cloned from chicken brain by RT-PCR. Using a pGL3-CRE-luciferase reporter system, we demonstrated that activation of each cSSTR expressed in CHO cells by cSST28, cSST14 and cCST14 treatment could inhibit forskolin-induced luciferase activity of CHO cells, indicating the functional coupling of all cSSTRs to Gi protein(s). Interestingly, cSSTR1-4 expressed in CHO cells could be activated by cSST28, cSST14 and cCST14 with high potencies, suggesting that they may function as the receptors common for these peptides. In contrast, cSSTR5 could be potently activated by cSST28 only, indicating that it is a cSST28-specific receptor. Using RT-PCR, wide expression of cSSTRs was detected in chicken tissues including pituitary. In accordance with their expression in pituitary, cSST28, cSST14, and cCST14 were demonstrated to inhibit basal and novel cGHRH1-27NH2-induced GH secretion in cultured chicken pituitary cells dose-dependently (0-10nM) by Western blot analysis, suggesting the involvement of cSSTR(s) common for these peptides in mediating their inhibitory actions. Collectively, our study establishes a molecular basis to elucidate the roles of SST/CST in birds and provide insights into the roles of SST/CST in vertebrates, such as their conserved actions on pituitary.

Heavy rainfall associated with a strong El Nino caused over $150 million in landslide damage in the 10-county San Francisco Bay region during the winter and spring of 1998. A team of USGS scientists collected information on landslide locations and damage costs. Napa County was relatively unaffected in comparison to other counties in the region with approximately $1.1 million in damages assessed.

Heavy rainfall associated with a strong El Nino caused over $150 million in landslide damage in the 10-county San Francisco Bay region during the winter and spring of 1998. A team of USGS scientists collected information on landslide locations and damage costs. In Alameda County more than $20 million in damages were assessed. Debris flows occurred in rural portions of the county, but were only responsible for $400 thousand in damages.

El Nino.Southern Oscillation (ENSO) is the dominant mode of interannual variability in the tropical atmosphere. ENSO could potentially impact local and global aerosol properties through atmospheric circulation anomalies and teleconnections. By analyzing aerosol properties, including aerosol optical depth (AOD) and Angstrom exponent (AE; often used as a qualitative indicator of aerosol particle size) from the Moderate Resolution Imaging Spectrometer, the Multiangle Imaging Spectroradiometer and the Sea ]viewing Wide Field ]of ]view Sensor for the period 2000.2011, we find a strong correlation between the AE data and the multivariate ENSO index (MEI) over the tropical Pacific. Over the western tropical Pacific (WTP), AE increases during El Nino events and decreases during La Nina events, while the opposite is true over the eastern tropical Pacific (ETP). The difference between AE anomalies in the WTP and ETP has a higher correlation coefficient (>0.7) with the MEI than the individual time series and could be considered another type of ENSO index. As no significant ENSO correlation is found in AOD over the same region, the change in AE (and hence aerosol size) is likely to be associated with aerosol composition changes due to anomalous meteorological conditions induced by the ENSO. Several physical parameters or mechanisms that might be responsible for the correlation are discussed. Preliminary analysis indicates surface wind anomaly might be the major contributor, as it reduces sea ]salt production and aerosol transport during El Nino events. Precipitation and cloud fraction are also found to be correlated with tropical Pacific AE. Possible mechanisms, including wet removal and cloud shielding effects, are considered. Variations in relative humidity, tropospheric ozone concentration, and ocean color during El Nino have been ruled out. Further investigation is needed to fully understand this AE ]ENSO covariability and the underlying physical processes responsible for

Heavy rainfall associated with a strong El Nino caused over $150 million in landslide damage in the 10-county San Francisco Bay region during the winter and spring of 1998. A team of USGS scientists collected information on landslide locations and damage costs. About $55 million in damages were assessed in San Mateo County. The only fatality attributed to landsliding in the region during the period occurred in San Mateo County near Loma Mar.

With the Zebiak-Cane (ZC) model, the initial error that has the largest effect on ENSO prediction is explored by conditional nonlinear optimal perturbation (CNOP). The results demonstrate that CNOP-type errors cause the largest prediction error of ENSO in the ZC model. By analyzing the behavior of CNOP- type errors, we find that for the normal states and the relatively weak EI Nino events in the ZC model, the predictions tend to yield false alarms due to the uncertainties caused by CNOP. For the relatively strong EI Nino events, the ZC model largely underestimates their intensities. Also, our results suggest that the error growth of EI Nino in the ZC model depends on the phases of both the annual cycle and ENSO. The condition during northern spring and summer is most favorable for the error growth. The ENSO prediction bestriding these two seasons may be the most difficult. A linear singular vector (LSV) approach is also used to estimate the error growth of ENSO, but it underestimates the prediction uncertainties of ENSO in the ZC model. This result indicates that the different initial errors cause different amplitudes of prediction errors though they have same magnitudes. CNOP yields the severest prediction uncertainty. That is to say, the prediction skill of ENSO is closely related to the types of initial error. This finding illustrates a theoretical basis of data assimilation. It is expected that a data assimilation method can filter the initial errors related to CNOP and improve the ENSO forecast skill.

The role of Ni(NO3)2 in the preparation of a magnetic activated carbon is reported in this paper.Magnetic coal-based activated carbons (MCAC) were prepared from Taixi anthracite with low ash content in the presence of Ni(NO3)2.The MCAC materials were characterized by a vibrating sample magnetometer (VSM),X-ray diffraction (XRD),a scanning electric microscope (SEM),and by N2 adsorption.The cylindrical precursors and derived char were also subjected to thermogravimetric analysis to compare their behavior of weight losses during carbonization.The results show that MCAC has a larger surface area (1074 m2/g) and a higher pore volume (0.5792 cm3/g) with enhanced mesopore ratio (by about 10％).It also has a high saturation magnetization (1.6749 emu/g) and low coercivity (43.26 Oe),which allows the material to be magnetically separated.The MCAC is easily magnetized because the nickel salt is converted into Ni during carbonization and activation.Metallic Ni has a strong magnetism on account of electrostatic interaction.Added Ni(NO3)2 catalyzes the carbonization and activation process by accelerating burn off of the carbon,which contributes to the development of mesopores and macropores in the activated carbon.

Full Text Available Extreme climatic oscillation has been the subject of global attention. The purpose of this study is to explore the response of extreme precipitation to solar activity and El Nino events in typical regions of the Loess Plateau—a case study in the Yan’an area. The precipitation data was from nine weather stations in Yan’an and the sunspot number and the Southern Oscillation Index (SOI were from 1951 to 2015. The results show that maximum precipitation occurred mainly at the peak sunspot number or 2a near it and the sunspot number minimum and valley values were not significantly correlated. The results of Morlet wavelet showed that a 41-year period of precipitation was the most obvious within the 64-year scale. Similarly, sunspot number showed a 16-year periodic variability. Correlation analyses of the 16-year and 41-year scales demonstrated that the relationships between precipitation and sunspot number were close. In addition, extreme precipitation often occurred in the year following El Nino events. According to 10-year moving average curves, precipitation generally showed a downward trend when SOI was negative. The results indicate that solar activity and El Nino events had significant impacts on precipitation in typical regions of the Loess Plateau.

The Humboldt Current System is one of the most important coastal upwelling system with an intense oxygen minimum zone, a high productivity and an important fishery activity. Every 2 to 7 years, ENSO events profoundly alter the environmental landscape of the system for several months. The ENSO warm phase, El Nino, is characterized by high sea surface temperature and low nutrient and chlorophyll concentration. A regional coupled physical-biogeochemical model is used to describe and understand the physical-biogeochemical coupled processes involved in the decrease of phytoplankton during El Nino, with a particular focus on the strong events. Comparison between observational data from surveys and satellites with model outputs show that our model configuration is able to reproduce the inter-annual dynamic variability off the Peruvian coast and the impacts of El Niño events. Temperature and sea level anomalies increase, while chlorophyll and nutrients concentration decrease. Passages of strong coastal-trapped waves during El Niño deepen both the thermocline and the nutricline and chlorophyll concentrations decrease. The upwelling intensity weakens because of a zonal geostrophic current flowing toward the coast. We show that the depth of upwelled waters does not change considerably, however their nitrate concentration decreases dramatically limiting the phytoplankton growth. We also illustrate that eddies also play an important role in nitrate loss during El Nino by increasing the offshore subduction.

The Advanced Along-Track Scanning Radiometer (AATSR) was launched on Envisat in March 2002. The AATSR instrument is a highly stable self-calibrating radiometer designed to make precise and accurate global Sea-Surface Temperature (SST) measurements. These data, when added to the large data set collected from its predecessors ATSR and ATSR-2, will provide a long-term record of SST measurements (>15 years) that can be used for independent monitoring and detecting of climate change. The formal specifications require that retrieved AATSR SST values achieve an absolute accuracy of better than ± 0.5 K, with ± 0.3 K (one sigma) adopted by the project as the target accuracy. An intensive SST validation programme has been in operation since launch that involves validating retrieved AATSR SST values against a) SST data retrieved from other satellite sensors such as AVHRR and MODIS b) a global network of buoy derived SST measurements and c) SST values determined from in-situ data collected from high-precision radiometers. This presentation will summarise the AATSR SST validation programme and will show that AATSR is currently meeting its objective to determine accurate global SST measurements to within 0.3 K (one sigma).

The ''Initial Single-Shell Tank System Performance Assessment for the Hanford Site [1] (SST PA) presents the analysis of the long-term impacts of residual wastes assumed to remain after retrieval of tank waste and closure of the SST farms at the US Department of Energy (DOE) Hanford Site. The SST PA supports key elements of the closure process agreed upon in 2004 by DOE, the Washington State Department of Ecology (Ecology), and the US Environmental Protection Agency (EPA). The SST PA element is defined in Appendix I of the ''Hanford Federal Facility Agreement and Consent Order'' (HFFACO) (Ecology et al. 1989) [2], the document that establishes the overall closure process for the SST and double-shell tank (DST) systems. The approach incorporated in the SST PA integrates substantive features of both hazardous and radioactive waste management regulations into a single analysis. The defense-in-depth approach used in this analysis defined two major engineering barriers (a surface barrier and the grouted tank structure) and one natural barrier (the vadose zone) that will be relied on to control waste release into the accessible environment and attain expected performance metrics. The analysis evaluates specific barrier characteristics and other site features that influence contaminant migration by the various pathways. A ''reference'' case and a suite of sensitivity/uncertainty cases are considered. The ''reference case'' evaluates environmental impacts assuming central tendency estimates of site conditions. ''Reference'' case analysis results show residual tank waste impacts on nearby groundwater, air resources; or inadvertent intruders to be well below most important performance objectives. Conversely, past releases to the soil, from previous tank farm operations, are shown to have groundwater impacts that re significantly above most performance objectives. Sensitivity

Methods and approaches are discussed that identify and filter off affecting factors (noise) above primary signals, based on the Adaptive-Network-Based Fuzzy Inference System. Influences of the zonal winds in equatorial castern and middle/western Pacific on the SSTA in the equatorial region and their contribution to the latter are diagnosed and verified with observations of a number of significant El Nino and La Nina episodes. New viewpoints are proposed. The method of wavelet decomposition and reconstruction are used to build a predictive model based on independent domains of frequency, which shows some advantages in composite prediction and prediction validity. The methods presented above are of non-linearity, error-allowing and auto-adaptive / learning.in addition to rapid and easy access, illustrative and quantitative presentation, and analyzed results that agree generally with facts. They are useful in diagnosing and predicting the El Nino and La Nina problems that are just roughly described in dynamics.

In the framework of the Cherenkov Telescope Array (CTA) Observatory, the Italian National Institute of Astrophysics (INAF) has recently inaugurated in Sicily (Italy), at the Serra La Nave astronomical site (on the slopes of Mount Etna), a dual-mirror prototype (ASTRI SST-2M) of the CTA small size class of telescopes. It is planned to install up to 70 small size telescopes in the southern CTA site, in order to allow the study of the gamma rays from a few TeV up to hundreds of TeV. The ASTRI SST-2M telescope prototype has been developed following an end-to-end approach. According to this philosophy, the telescope includes structure, primary and secondary mirrors, camera, software and hardware for control/acquisition and data handling. The camera, almost completed, has been designed to cover a field of view of 9.6 degrees. After the full implementation of the prototype, a remarkable improvement in terms of technology advancement and performance will come from the operation of the ASTRI mini-array, led within the CTA collaboration by INAF in synergy with the Universidade de Sao Paulo (Brazil) and the North-West University (South Africa). The ASTRI mini-array will be composed of at least 9 ASTRI SST-2M units and it is proposed to be installed at the CTA southern site as part of its pre-production phase. Apart from the assessment of a number of technological aspects related to CTA, the ASTRI mini-array will extend and improve the flux sensitivity compared with the current experiments (HESS, MAGIC and VERITAS) in the 5 - 300 TeV energy range.

The Indian Ocean (IO) sea surface temperature (SST) was analyzed by using empirical orthogonal function (EOF), and the leading mode of Indian Ocean (LMIO) SST was extracted. The major spatial and temporal characters of LMIO were discussed, and the relationships between LMIO with Indian summer monsoon (ISM) and with China summer rainfalls (CSR) were investigated, then the impacts of LMIO on Asian summer monsoon (ASM) circulation were explored. Some notable results are obtained: The significant evolutional characters of LMIO are the consistent warming trend of almost the whole IO basin,the distinctive quasi-3- and quasi-ll-yr oscillations and remarkably interdecadal warming in 1976/1977 and1997/1998, respectively. The LMIO impaired the lower level circulation of ISM and was closely related with the climate trend of CSR. It was associated with the weakening of South Asian high, the easterly winds south of the Tibetan Plateau, and the cross-equatorial flows over 10°-20°N, 40°-110°E at the upper level; with the strengthening of Somali cross-equatorial jet but the weakening of the circulation of ISM in the sector of India, the strengthening of south wind over the middle and lower reaches of Yangtze River and South China but the weakening of southwesterly winds over North China at lower level and with the increasing of surface pressure over the Asian Continent. Changes in the moisture flux transports integrated vertically over the whole troposphere associated with LMIO are similar to those in the lower level circulation. To sum up, the significant SST increasing trend of IO basin was one of the important causes for weakening of the ASM circulation and the southwards shifting of China summer rainband.

SST-GATE (Small Size Telescope - GAmma-ray Telescope Elements) is a 4-metre telescope designed as a prototype for the Small Size Telescopes (SST) of the Cherenkov Telescope Array (CTA), a major facility for the very high energy gamma-ray astronomy of the next three decades. In this 100-telescope array there will be 70 SSTs, involving a design with an industrial view aiming at long-term service, low maintenance effort and reduced costs. More than a prototype, SST-GATE is also a fully functional telescope that shall be usable by scientists and students at the Observatoire de Meudon for 30 years. The Telescope Control System (TCS) is designed to work either as an element of a large array driven by an array controller or in a stand-alone mode with a remote workstation. Hence it is built to be autonomous with versatile interfacing; as an example, pointing and tracking —the main functions of the telescope— are managed onboard, including astronomical transformations, geometrical transformations (e.g. telescope bending model) and drive control. The core hardware is a CompactRIO (cRIO) featuring a real-time operating system and an FPGA. In this paper, we present an overview of the current status of the TCS. We especially focus on three items: the pointing computation implemented in the FPGA of the cRIO —using CORDIC algorithms— since it enables an optimisation of the hardware resources; data flow management based on OPCUA with its specific implementation on the cRIO; and the use of an EtherCAT field-bus for its ability to provide real-time data exchanges with the sensors and actuators distributed throughout the telescope.

The present study examines processes governing the interannual variation of MLT in the eastern equatorial Pacific.Processes controlling the interannual variation of mixed layer temperature (MLT) averaged over the Nino-3 domain (5 deg N-5 deg S, 150 deg-90 deg W) are studied using an ocean data assimilation product that covers the period of 1993-2003. The overall balance is such that surface heat flux opposes the MLT change but horizontal advection and subsurface processes assist the change. Advective tendencies are estimated here as the temperature fluxes through the domain's boundaries, with the boundary temperature referenced to the domain-averaged temperature to remove the dependence on temperature scale. This allows the authors to characterize external advective processes that warm or cool the water within the domain as a whole. The zonal advective tendency is caused primarily by large-scale advection of warm-pool water through the western boundary of the domain. The meridional advective tendency is contributed to mostly by Ekman current advecting large-scale temperature anomalies through the southern boundary of the domain. Unlike many previous studies, the subsurface processes that consist of vertical mixing and entrainment are explicitly evaluated. In particular, a rigorous method to estimate entrainment allows an exact budget closure. The vertical mixing across the mixed layer (ML) base has a contribution in phase with the MLT change. The entrainment tendency due to the temporal change in ML depth is negligible compared to other subsurface processes. The entrainment tendency by vertical advection across the ML base is dominated by large-scale changes in upwelling and the temperature of upwelling water. Tropical instability waves (TIWs) result in smaller-scale vertical advection that warms the domain during La Nina cooling events. However, such a warming tendency is overwhelmed by the cooling tendency associated with the large-scale upwelling by a factor of

New sea surface height measurements from the TOPEX/Poseidon satellite show that the sea level and temperature of the entire Pacific is 'out of balance,' including a large area of abnormally cool water along the west coast of North America that scientists say will influence regional weather patterns along the west coast of the Americas this summer. Southern California's seasonal 'June gloom' weather, caused by a marine layer that traps smog over the Los Angeles basin, may linger throughout the summer as a result, according to oceanographer Dr. William Patzert of JPL. 'Our data certainly show that the unusual oceanic climatic conditions that gave rise to El Nino and La Nina are not returning to a normal state.' he said. 'Our planet's climate system continues to exhibit rather wild behavior. These large warm and cold, high and low sea levels are slow-developing and long-lasting, and will certainly influence global climate and weather for the coming summer and into next fall.' The unusually cool water (areas of lower sea level shown in blue and purple) extends from the Gulf of Alaska along the North American coast, sweeping south-westward from Baja California, where it merges with the remnants of La Nina. The La Nina phenomenon's cool, lower sea levels across the equator continue to weaken and break into (purple) patches. The northwest Pacific continues to be warmer than normal, though the variations from normal are not as great as in recent months. Areas where the Pacific Ocean is normal appear in green. The data represented in the image were collected from May 12-22.TOPEX/Poseidon's sea-surface height measurements have provided scientists with a detailed view of the 1998-99 La Nina and the 1997-98 El Nino because the satellite's altimeter measures the changing sea-surface height with unprecedented precision. In this image, the purple areas are about 18 centimeters (7 inches) below normal, creating a deficit in the heat supply to the surface waters. The white areas

Sea surface temperature (SST) is one of the most important parameters in monitoring ecosystem health in the marine and coastal environment. Coastal ecosystem is largely dependent on ambient temperature and temperature fronts for marine/coastal habitat and its sustainability. Hence, thermal pollution is seen as a severe threat for ecological health of coastal waters across the world. Mumbai is one of the largest metropolises of the world and faces severe domestic and industrial effluent disposal problem, of which thermal pollution is a major issue with policy-makers and environmental stakeholders. This study attempts to understand the long-term SST variation in the coastal waters off Mumbai, on the western coast of India, and to identify thermal pollution zones. Analysis of SST trends in the near-coastal waters for the pre- and post-monsoon seasons from the year 2004 to the year 2010 has been carried out using Moderate Resolution Imaging Spectro-radiometer (MODIS) Thermal Infra-red (TIR) bands. SST is calculated with the help of bands 31 and 32 using split window method. Several statistical operations were then applied to find the seasonal averages in SST and the standard deviation of SST in the study area. Maximum variation in SST was found within a perpendicular distance of 5 km from the shoreline during the study period. Also, a warm water mass was found to form consistently off coast during the winter months. Several anthropogenic sources of thermal pollution could be identified which were found to impact various locations along the coast.

Hepatocellular carcinoma (HCC) is the sixth most common malignancy worldwide. Different signalling pathways have been identified to be implicated in the pathogenesis of HCC; among these, GH, IGF and somatostatin (SST) pathways have emerged as some of the major pathways implicated in the development of HCC. Physiologically, GH-IGF-SST system plays a crucial role in liver growth and development since GH induces IGF1 and IGF2 secretion and the expression of their receptors, involved in hepatocytes cell proliferation, differentiation and metabolism. On the other hand, somatostatin receptors (SSTRs) are exclusively present on the biliary tract. Importantly, the GH-IGF-SST system components have been indicated as regulators of hepatocarcinogenesis. Reduction of GH binding affinity to GH receptor, decreased serum IGF1 and increased serum IGF2 production, overexpression of IGF1 receptor, loss of function of IGF2 receptor and appearance of SSTRs are frequently observed in human HCC. In particular, recently, many studies have evaluated the correlation between increased levels of IGF1 receptors and liver diseases and the oncogenic role of IGF2 and its involvement in angiogenesis, migration and, consequently, in tumour progression. SST directly or indirectly influences tumour growth and development through the inhibition of cell proliferation and secretion and induction of apoptosis, even though SST role in hepatocarcinogenesis is still opened to argument. This review addresses the present evidences suggesting a role of the GH-IGF-SST system in the development and progression of HCC, and describes the therapeutic perspectives, based on the targeting of GH-IGF-SST system, which have been hypothesised and experimented in HCC.

A single-mirror small-size (SST-1M) Davies-Cotton telescope with a dish diameter of 4 m has been built by a consortium of Polish and Swiss institutions as a prototype for one of the proposed small-size telescopes for the southern observatory of the Cherenkov Telescope Array (CTA). The design represents a very simple, reliable, and cheap solution. The mechanical structure prototype with its drive system is now being tested at the Institute of Nuclear Physics PAS in Krakow. Here we present the design of the prototype and results of the performance tests of the structure and the drive and control system.

The Cherenkov Telescope Array (CTA), the next generation very high energy gamma-rays observatory, will consist of three types of telescopes: large (LST), medium (MST) and small (SST) size telescopes. The SSTs are dedicated to the observation of gamma-rays with energy between a few TeV and a few hundreds of TeV. The SST array is expected to have 70 telescopes of different designs. The single-mirror small size telescope (SST-1 M) is one of the proposed telescope designs under consideration for the SST array. It will be equipped with a 4 m diameter segmented mirror dish and with an innovative camera based on silicon photomultipliers (SiPMs). The challenge is not only to build a telescope with exceptional performance but to do it foreseeing its mass production. To address both of these challenges, the camera adopts innovative solutions both for the optical system and readout. The Photo-Detection Plane (PDP) of the camera is composed of 1296 pixels, each made of a hollow, hexagonal light guide coupled to a hexagonal SiPM designed by the University of Geneva and Hamamatsu. As no commercial ASIC would satisfy the CTA requirements when coupled to such a large sensor, dedicated preamplifier electronics have been designed. The readout electronics also use an innovative approach in gamma-ray astronomy by adopting a fully digital approach. All signals coming from the PDP are digitized in a 250 MHz Fast ADC and stored in ring buffers waiting for a trigger decision to send them to the pre-processing server where calibration and higher level triggers will decide whether the data are stored. The latest generation of FPGAs is used to achieve high data rates and also to exploit all the flexibility of the system. As an example each event can be flagged according to its trigger pattern. All of these features have been demonstrated in laboratory measurements on realistic elements and the results of these measurements will be presented in this contribution.

We present a new illumination technique for the camera relative gain calibration of the ASTRI SST-2M Cherenkov telescope. The camera illumination is achieved by means of an optical fiber that diffuses the light inside a protective PMMA window above the focal plane. We report the encouraging results of the development tests carried out on two PMMA window prototypes illuminated by a standard optical fiber. We checked also the reliability of the method by a series of ray tracing simulations for different scattering models and PMMA window shapes finding good agreement with experimental results.

the da Silva, Young, Levitus COADS analysis. The overall results from our analysis suggest an increase (decrease) of the hydrologic cycle during ENSO warm (cold) events at the rate of about 5 W/sq m per K of SST change. Model results agree reasonably well with this estimate of sensitivity. This rate is slightly less than that which would be expected for constant relative humidity over the tropical oceans. There remain, however, significant quantitative uncertainties in cloud forcing changes in the models as compared to observations. These differences are examined in relationship to model convection and cloud parameterizations Analysis of the possible sampling and measurement errors compared to systematic model errors is also presented.

The global atmospheric temperature anomalies of Earth reached a maximum in 1998 which has not been exceeded during the subsequent 10 years. The global anomalies are calculated from the average of climate effects occurring in the tropical and the extratropical latitude bands. El Nino/La Nina effects in the tropical band are shown to explain the 1998 maximum while variations in the background of the global anomalies largely come from climate effects in the northern extratropics. These effects do not have the signature associated with CO2 climate forcing. However, the data show a small underlying positive trend that is consistent with CO2 climate forcing with no-feedback.

Based on coral proxies we reconstructed the western Pacific warm pool sea surface temperature (SST) since 1644 AD.High-frequency reconstructions are based on eight high-pass filtered coral series and raw reconstructions are derived from eight unfiltered coral series,respectively.Validation and comparison with other SST/temperature series show that the reconstructed warm pool SST is highly reliable.The leading periods of warm pool SST are ～2.1,～2.3,～2.9,～3.6,～3.8,and 80.7-year during the last ～360 years.The warm pool SST exhibits some obvious long-term trends:an upward trend of 0.04℃ per century for the period of 1644-1825,while a decreasing trend of 0.24℃ per century for the period of 1826-1885,and then a remarkable warming trend of 0.28℃ per century taking place between 1886 and 2006.Especially,the SST shows the strongest trend of 0.67℃ increase per century during the last 50 years,a warming unprecedented since 1644 AD.On interannual timescale,the connections between ENSO and the warm pool SST are robust during the reconstruction period.There are significant correlations between the warm pool SST and summer precipitation of the Yellow River basin and Huaihe River basin;the correlation coefficients are-0.44 in reconstruction period (1880-1949 AD) and -0.46 in instrumental period (1950-2005 AD) respectively.This relationship is also found between flooddrought index and the warm pool SST during the past 360 years,and their correlation coefficients are -0.20 in reconstruction period and -0.46 in instrumental period respectively,significant at the 0.01 level.On interdecadal timescale,this connection is more robust,and the correlation coefficient of the low-pass filtered components is -0.42 during the whole period (1644-2000 AD).When the warm pool is warmer than normal,the precipitation is usually below the normal in the Yellow River and Huaihe River basin.On the contrary,when the warm pool is colder than the normal,there may be more precipitation

Based on coral proxies we reconstructed the western Pacific warm pool sea surface temperature (SST) since 1644 AD. High-frequency reconstructions are based on eight high-pass filtered coral series and raw reconstructions are derived from eight unfiltered coral series, respectively. Validation and comparison with other SST/temperature series show that the reconstructed warm pool SST is highly reliable. The leading periods of warm pool SST are ~2.1, ~2.3, ~2.9, ~3.6, ~3.8, and 80.7-year during the last ~360 years. The warm pool SST exhibits some obvious long-term trends: an upward trend of 0.04℃ per century for the period of 1644―1825, while a decreasing trend of 0.24℃ per century for the period of 1826―1885, and then a remarkable warming trend of 0.28℃ per century taking place between 1886 and 2006. Especially, the SST shows the strongest trend of 0.67℃ increase per century during the last 50 years, a warming unprecedented since 1644 AD. On interannual timescale, the connections between ENSO and the warm pool SST are robust during the reconstruction period. There are significant corre- lations between the warm pool SST and summer precipitation of the Yellow River basin and Huaihe River basin; the correlation coefficients are -0.44 in reconstruction period (1880―1949 AD) and -0.46 in instrumental period (1950―2005 AD) respectively. This relationship is also found between flooddrought index and the warm pool SST during the past 360 years, and their correlation coefficients are -0.20 in reconstruction period and-0.46 in instrumental period respectively, significant at the 0.01 level. On interdecadal timescale, this connection is more robust, and the correlation coefficient of the low-pass filtered components is -0.42 during the whole period (1644―2000 AD). When the warm pool is warmer than normal, the precipitation is usually below the normal in the Yellow River and Huaihe River basin. On the contrary, when the warm pool is colder than the normal

Over the last decade there have been commercial TOF-PET scanners constructed using Photo-Multiplier Tubes (PMT) that have achieved View the MathML source~500ps FWHM Coincidence Time Resolution (CTR). A new device known as the Silicon PhotoMultiplier (SiPM) has the potential to overcome some of the limitations of the PMT. Therefore implementing a SiPM based TOF-PET scanner is of high interest. Recently Philips has introduced a TOF-PET scanner that uses digital Silicon PhotoMultipliers (d-SiPMs) which has a CTR of 350 ps. Here we will report on the timing performance of two Hamamatsu 3×3 mm2 analogue-SiPMs read out with the NINO ASIC: this is an ultra-fast amplifier/discriminator with a differential architecture. The differential architecture is very important since the single-ended readout uses the ground as the signal return; as the ground is also the reference level for the discriminators, the result is high crosstalk and degraded time resolution. However differential readout allows the scaling up from a si...

Highlights: • Steady state superconducting tokamak (SST-1). • Pre-ionization. • ECRH. • 0-D model. - Abstract: Electron cyclotron resonance (ECRH) assisted break-down and start-up is considered as useful tool towards the discharge initiation in superconducting tokamaks, where the vacuum vessels and the cryostats are usually electrically continuous with thick walls. ECH pre-ionizations are known to reduce the required central solenoid swing induced toroidal electric field, E significantly. The Steady state superconducting tokamak (SST-1, R = 1.1 m, a = 0.2 m) has achieved successful plasma break-down and subsequent current ramp-up with ECH pre-ionizations in both fundamental mode and second harmonic modes with E ∼ 0.35 V/m. This work has discussed an appropriate simulation model and validated its results with experiments for the ECRH assisted breakdown and start-up, for both 1st harmonic ordinary mode (O1) and 2nd harmonic extra-ordinary mode (X2), in SST-1 for hydrogen plasmas, where the loop voltage is limited to 0.35 V/m. The simulation model is a zero-dimensional (0-D) model. In this model five temporal equations are solved for spatially-uniform plasma. The primary findings of this investigation has been the determination of the threshold ECRH power for successful pre-ionization of plasma in SST-1 and validations of the results with experimental findings in SST-1.

ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) is a flagship project of the Italian Ministry of Research and led by the Italian National Institute of Astrophysics (INAF). One of its aims is to develop, within the Cherenkov Telescope Array (CTA) framework, an end-to-end small-sized telescope prototype in a dual-mirror configuration (SST-2M) in order to investigate the energy range E ~ 1-100 TeV. A long-term goal of the ASTRI program is the production of an ASTRI/CTA mini-array composed of seven SST-2M telescopes. The prototype, named ASTRI SST-2M, is seen as a standalone system that needs only network and power connections to work. The software system that is being developed to control the prototype is the base for the Mini-Array Software System (MASS), which has the task to make possible the operation of both the ASTRI SST-2M prototype and the ASTRI/CTA mini-array. The scope of this contribution is to give an overview of the hardware and software architecture adopted for the ASTRI SST- 2M prototype, showing how to apply state of the art industrial technologies to telescope control and monitoring systems.

The somatostatin receptor 2 (sst2) is the pharmacological target of somatostatin analogs that are widely used in the diagnosis and treatment of human neuroendocrine tumors. We have recently shown that the stable somatostatin analogs octreotide and pasireotide (SOM230) stimulate distinct patterns of sst2 receptor phosphorylation and internalization. Like somatostatin, octreotide promotes the phosphorylation of at least six carboxyl-terminal serine and threonine residues namely S341, S343, T353, T354, T356 and T359, which in turn leads to a robust receptor endocytosis. Unlike somatostatin, pasireotide stimulates a selective phosphorylation of S341 and S343 of the human sst2 receptor followed by a partial receptor internalization. Here, we show that exchange of S341 and S343 by alanine is sufficient to block pasireotide-driven internalization, whereas mutation of T353, T354, T356 and T359 to alanine is required to strongly inhibited both octreotide- and somatostatin-induced internalization. Yet, combined mutation of T353, T354, T356 and T359 is not sufficient to prevent somatostatin-driven β-arrestin mobilization and receptor desensitization. Replacement of all fourteen carboxyl-terminal serine and threonine residues by alanine completely abrogates sst2 receptor internalization and β-arrestin mobilization in HEK293 cells. Together, our findings demonstrate for the first time that agonist-selective sst2 receptor internalization is regulated by multi-site phosphorylation of its carboxyl-terminal tail.

The interannual variability of autumn precipitation over South China and its relationship with atmospheric circulation and SST anomalies are examined using the autumn precipitation data of 160 stations in China and the NCEP-NCAR reanalysis dataset from 1951 to 2004. Results indicate a strong interannual variability of autumn precipitation over South China and its positive correlation with the autumn western Pacific subtropical high (WPSH). In the flood years, the WPSH ridge line lies over the south of South China and the strengthened ridge over North Asia triggers cold air to move southward. Furthermore, there exists a significantly anomalous updraft and cyclone with the northward stream strengthened at 850 hPa and a positive anomaly center of meridional moisture transport strengthening the northward warm and humid water transport over South China. These display the reverse feature in drought years. The autumn precipitation interannual variability over South China correlates positively with SST in the western Pacific and North Pacific, whereas a negative correlation occurs in the South Indian Ocean in July. The time of the strongest lag-correlation coefficients between SST and autumn precipitation over South China is about two months, implying that the SST of the three ocean areas in July might be one of the predictors for autumn precipitation interannual variability over South China. Discussion about the linkage among July SSTs in the western Pacific, the autumn WPSH and autumn precipitation over South China suggests that SST anomalies might contribute to autumn precipitation through its close relation to the autumn WPSH.

In the framework of the international Cherenkov Telescope Array (CTA) observatory, the Italian National Institute for Astrophysics (INAF) has developed a dual mirror, small sized, telescope prototype (ASTRI SST-2M), installed in Italy at the INAF observing station located at Serra La Nave, Mt. Etna. The ASTRI SST-2M prototype is the basis of the ASTRI telescopes that will form the mini-array proposed to be installed at the CTA southern site during its preproduction phase. This contribution presents the solutions implemented to realize the monitoring system for the Information and Communication Technology (ICT) infrastructure of the ASTRI SST-2M prototype. The ASTRI ICT monitoring system has been implemented by integrating traditional tools used in computer centers, with specific custom tools which interface via Open Platform Communication Unified Architecture (OPC UA) to the Alma Common Software (ACS) that is used to operate the ASTRI SST-2M prototype. The traditional monitoring tools are based on Simple Network Management Protocol (SNMP) and commercial solutions and features embedded in the devices themselves. They generate alerts by email and SMS. The specific custom tools convert the SNMP protocol into the OPC UA protocol and implement an OPC UA server. The server interacts with an OPC UA client implemented in an ACS component that, through the ACS Notification Channel, sends monitor data and alerts to the central console of the ASTRI SST-2M prototype. The same approach has been proposed also for the monitoring of the CTA onsite ICT infrastructures.

The SST-1M telescope is one of the prototypes under construction proposed to be part of the future Cherenkov Telescope Array. It uses a standard Davis-Cotton design for the optics and telescope structure, with a dish diameter of 4 meters and a large field-of-view of 9 degrees. The innovative camera design is composed of a photo-detection plane with 1296 pixels including entrance window, light concentrators, Silicon Photomultipliers (SiPMs), and pre-amplifier stages together with a fully digital readout and trigger electronics, DigiCam. In this contribution we give a general description of the analysis chain designed for the SST-1M prototype. In particular we focus on the calibration strategy used to convert the SiPM signals registered by DigiCam to the quantities needed for Cherenkov image analysis. The calibration is based on an online feedback system to stabilize the gain of the SiPMs, as well as dedicated events (dark count, pedestal, and light flasher events) to be taken during the normal operation of the...

We employ a statistical model of North Atlantic tropical cyclone (TC) tracks to investigate the relationship between sea-surface temperature (SST) and North American TC landfall rates. The track model is conditioned on summer SST in the tropical North Atlantic being in either the 19 hottest or the 19 coldest years in the period 1950-2005. For each conditioning many synthetic TCs are generated and landfall rates computed. Compared to direct analysis of historical landfall, the track model reduces the sampling error by projecting information from the entire basin onto the coast. There are 46% more TCs in hot years than cold in the model, which is highly significant compared to random sampling and corroborates well documented trends in North Atlantic TC number in recent decades. In the absence of other effects, this difference results in a significant increase in model landfall rates in hot years, uniform along the coast. Hot-cold differences in the geographic distribution of genesis and in TC propagation do not...

The Cherenkov Telescope Array (CTA) will be the world's first open observatory for very high energy gamma-rays. Around a hundred telescopes of different sizes will be used to detect the Cherenkov light that results from gamma-ray induced air showers in the atmosphere. Amongst them, a large number of Small Size Telescopes (SST), with a diameter of about 4 m, will assure an unprecedented coverage of the high energy end of the electromagnetic spectrum (above ~1TeV to beyond 100 TeV) and will open up a new window on the non-thermal sky. Several concepts for the SST design are currently being investigated with the aim of combining a large field of view (~9 degrees) with a good resolution of the shower images, as well as minimizing costs. These include a Davies-Cotton configuration with a Geiger-mode avalanche photodiode (GAPD) based camera, as pioneered by FACT, and a novel and as yet untested design based on the Schwarzschild-Couder configuration, which uses a secondary mirror to reduce the plate-scale and to all...

One thousand and forty-nine sea surface isotherm maps during 1990～2000 were used to detect the Kuroshio axis off the coast of Japan. The current axis on the surface cannot be identified by just one indicative isotherm as is commonly done in deep water, but still there are complicated isotherms indicatives of the Kuroshio axis.Three types of isotherms indicatives of the surface axis of the Kuroshio are identified, which are nesting-warm-tongue-indicator, warm-tongue-isotherm-indicator, and isotherm-indicator. The occurrence frequency of NWTI-type is 72%, that of WTII-type is 19.1% and that of Ⅱ-type is 8.9%. The vector-based and raster-based methods were introduced and used to retrieve automatically the Kuroshio paths from SST data. The total retrieving percentage is 74% by the three methods, 52.3% by the vector method, 56.8% by one raster method and 49.6% by another raster method. For the NWTI-type, the total retrieving percentage is 91.3% by the three methods, 64.4% by the vector method, 75.9% by one raster method and 65% by another raster method. Using retrieving results of the Kuroshio axis from SST data,the Kuroshio path detour is analyzed during 1990～2000.

The convection over the tropical western Pacific warm pool influences significantly the atmospheric circulation and climate in East Asia. Thus, the precursory signals of the convection may be used in the forecast of summer climate in China. According to the present results, the June- July-August (JJA) mean convection intensity over the warm pool is significantly related to the precursory positive and negative sea surface temperatures (SSTs) in the warm pool and in the equatorial central and eastern Pacific, respectively. It is also related to the simultaneous negative surface temperatures west to the Philippines. The analysis on the SSTs associated with the convection over the warm pool in individual month of summer shows that for the convection in June and July, there are precursory SST signals in the warm pool and the equatorial central and eastern Pacific. Therefore, this study shows that only the convection in June and July, rather than that in August, has precursory SST signals, despite the existence of the precursory signals of the JJA mean convection. Accordingly, it is implied that the interaction among the warm pool, equatorial central and eastern Pacific, and the region west to the Philippines may exhibit distinct features in the precursory period (preceding winter and spring) and in the simultaneous period.

Full Text Available The computation of spherical harmonic coefficients of the Earth’s gravity field from satellite-to-satellite tracking (SST data and satellite gravity gradiometry (SGG data is considered. As long as the functional model related to SST data contains nuisance parameters (e.g. unknown initial state vectors, assembling of the corresponding normal matrix must be supplied with the back-substitution operation, so that the nuisance parameters are excluded from consideration. The traditional back-substitution algorithm, however, may result in large round-off errors. Hence an alternative approach, back-substitution at the level of the design matrix, is implemented. Both a stand-alone inversion of either type of data and a joint inversion of both types are considered. The conclusion drawn is that the joint inversion results in a much better model of the Earth’s gravity field than a standalone inversion. Furthermore, two numerical techniques for solving the joint system of normal equations are compared: (i the Cholesky method based on an explicit computation of the normal matrix, and (ii the pre-conditioned conjugate gradient method (PCCG, for which an explicit computation of the entire normal matrix is not needed. The comparison shows that the PCCG method is much faster than the Cholesky method.Key words. Earth’s gravity field, GOCE, satellite-tosatellite tracking, satellite gravity gradiometry, backsubstitution

SST trends measured in the Somalia region during the southwest monsoon season over the period 1982-2013 have shown the existence of a warming-cooling dipole. The positive spot, with a warming trend on the order of 0.37°C dec-1, is centered around 5.1°N-50.3°E and the negative one, with a trend on the order of -0.43°C dec-1, around 11.1°N-52.2°E. The migration of the Great Whirl (GW) over the last three decades at a speed of -0.3°C dec-1 in longitude and -0.6°C dec-1 in latitude was considered as the possible origin of the SST dipole. The displacement of the GW produces changes in the geostrophic currents which, in turn, generate changes in the amount of advected water from and to coast.

The dominant mode of July-August (JA) seasonal variability of Indian summer monsoon rainfall (ISMR) are obtained by performing empirical orthogonal function (EOF) analysis. The first dominant mode of ISMR and its relationships with the sea surface temperature (SST), pressure level wind and geopotential height (GPH) fields are examined using gridded datasets for the period 1979-2014. The principal component of the first leading mode (PC1) obtained in the EOF analysis of JA rainfall over Indian landmass is highly correlated with north-west and central India rainfall, and anti-correlated with east-equatorial Atlantic SST (EEASST). The positive EEASST anomaly intensifies the inter-tropical convergence zone over Atlantic and west equatorial Africa which generates stationary wave meridionally, as meridional transfer of energy is strong, as the influence of background jet-streams are minimal over North Africa and Europe. The anomalous positive and negative GPH are generated over sub-tropics and extra-tropics, respectively, due to the stationary wave. This increases the climatological background steep pressure gradient between sub-tropics and extra-tropics consisting of anomalous negative GPH field over north-west (NW) Europe and vice versa for negative EEASST anomaly. The anomalous positive GPH over NW Europe acts as center of action for the propagation of a Rossby wave train to NW India via Europe consisting of anomalous high over NW of India. This intensifies the Tibetan High westward which reinforces the outbreak of monsoon activities over central and NW India.

Full Text Available The intent of shielding functions in delayed detached-eddy simulation methods (DDES is to preserve the wall boundary layers as Reynolds-averaged Navier–Strokes (RANS mode, avoiding possible modeled stress depletion (MSD or even unphysical separation due to grid refinement. An entropy function fs is introduced to construct a DDES formulation for the k-ω shear stress transport (SST model, whose performance is extensively examined on a range of attached and separated flows (flat-plate flow, circular cylinder flow, and supersonic cavity-ramp flow. Two more forms of shielding functions are also included for comparison: one that uses the blending function F2 of SST, the other which adopts the recalibrated shielding function fd_cor of the DDES version based on the Spalart-Allmaras (SA model. In general, all of the shielding functions do not impair the vortex in fully separated flows. However, for flows including attached boundary layer, both F2 and the recalibrated fd_cor are found to be too conservative to resolve the unsteady flow content. On the other side, fs is proposed on the theory of energy dissipation and independent on from any particular turbulence model, showing the generic priority by properly balancing the need of reserving the RANS modeled regions for wall boundary layers and generating the unsteady turbulent structures in detached areas.

First Wall Components (FWC) of SST-1 tokamak, which are in the immediate vicinity of plasma, comprises of limiters, divertors, baffles, passive stabilizers designed to operate long duration (∼1000 s) discharges of elongated plasma. All FWC consist of copper alloy heat sink modules with SS cooling tubes brazed onto it, graphite tiles acting as armour material facing the plasma, and are mounted to the vacuum vessels with suitable Inconel support structures at inter-connected ring & port locations. The FWC are very recently assembled and commissioned successfully inside the vacuum vessel of SST-1 undergoing a rigorous quality control and checks at every stage of the assembly process. This paper will present the quality control aspects and checks of FWC from commencement of assembly procedure, namely material test reports, leak testing of high temperature baked components, assembled dimensional tolerances, leak testing of all welded joints, graphite tile tightening torques, electrical continuity and electrical isolation of passive stabilizers from vacuum vessel, baking and cooling hydraulic connections inside vacuum vessel.

The dominant mode of July-August (JA) seasonal variability of Indian summer monsoon rainfall (ISMR) are obtained by performing empirical orthogonal function (EOF) analysis. The first dominant mode of ISMR and its relationships with the sea surface temperature (SST), pressure level wind and geopotential height (GPH) fields are examined using gridded datasets for the period 1979-2014. The principal component of the first leading mode (PC1) obtained in the EOF analysis of JA rainfall over Indian landmass is highly correlated with north-west and central India rainfall, and anti-correlated with east-equatorial Atlantic SST (EEASST). The positive EEASST anomaly intensifies the inter-tropical convergence zone over Atlantic and west equatorial Africa which generates stationary wave meridionally, as meridional transfer of energy is strong, as the influence of background jet-streams are minimal over North Africa and Europe. The anomalous positive and negative GPH are generated over sub-tropics and extra-tropics, respectively, due to the stationary wave. This increases the climatological background steep pressure gradient between sub-tropics and extra-tropics consisting of anomalous negative GPH field over north-west (NW) Europe and vice versa for negative EEASST anomaly. The anomalous positive GPH over NW Europe acts as center of action for the propagation of a Rossby wave train to NW India via Europe consisting of anomalous high over NW of India. This intensifies the Tibetan High westward which reinforces the outbreak of monsoon activities over central and NW India.

This study explores the possibility of southern Indian Ocean (SIO) sea surface temperature (SST) as a modulator for the early phase of Indian summer monsoon and its possible physical mechanism. A dipole-like structure is obtained from the empirical orthogonal function (EOF) analysis which is similar to an Indian Ocean subtropical dipole (IOSD) found earlier. A subtropical dipole index (SDI) is defined based on the SST anomaly over the positive and negative poles. The regression map of rainfall over India in the month of June corresponding to the SDI during 1983-2013 shows negative patterns along the Western Ghats and Central India. However, the regression pattern is insignificant during 1952-1982. The multiple linear regression models and partial correlation analysis also indicate that the SDI acts as a dominant factor to influence the rainfall over India in the month of June during 1983-2013. The similar result is also obtained with the help of composite rainfall over the land points of India in the month of June for positive (negative) SDI events. It is also observed that the positive (negative) SDI delays (early) the onset dates of Indian monsoon over Kerala during the time domain of our study. The study is further extended to identify the physical mechanism of this impact, and it is found that the heating (cooling) in the region covering SDI changes the circulation pattern in the SIO and hence impacts the progression of monsoon in India.

A composite map produced by combining 90 passes of SST data show good agreement with conventional GEM models. The SEASAT altimeter data were deduced and found to agree with both the SST and GEM fields. The maps are dominated (especially in the east) by a pattern of roughly east-west anomalies with a transverse wavelength of about 2000 km. Comparison with regional bathymetric data shows a remarkedly close correlation with plate age. Most anomalies in the east half of the Pacific could be partly caused by regional differences in plate age. The amplitude of these geoid or gravity anomalies caused by age differences should decrease with absolute plate age, and large anomalies (approximately 3 m) over old, smooth sea floor may indicate a further deeper source within or perhaps below the lithosphere. The possible plume size and ascent velocity necessary to supply deep mantle material to the upper mantle without complete thermal equilibration was considered. A plume emanating from a buoyant layer 100 km thick and 10,000 times less viscous than the surrounding mantle should have a diameter of about 400 km and must ascend at about 10 cm/yr to arrive still anomalously hot in the uppermost mantle.

ASTRI is a Flagship Project of the Italian Ministry of Education, University and Research, led by the Italian National Institute of Astrophysics, INAF. One of the main aims of the ASTRI Project is the design, construction and verification on-field of a dual mirror (2M) end-to-end prototype for the Small Size Telescope (SST) envisaged to become part of the Cherenkov Telescope Array. The ASTRI SST-2M prototype adopts the Schwarzschild-Couder design, and a camera based on SiPM (Silicon Photo Multiplier); it will be assembled at the INAF astronomical site of Serra La Nave on mount Etna (Catania, Italy) within mid 2014, and will start scientific validation phase soon after. The peculiarities of the optical design and of the SiPM bandpass pushed towards specifically optimized choices in terms of reflective coatings for both the primary and the secondary mirror. In particular, multi-layer dielectric coatings, capable of filtering out the large Night Sky Background contamination at wavelengths $\\lambda \\gtrsim 700$ n...

Spatial Information about rice planting season (RPS) in a wide areas, particularly during periods of El Nino, is important to support an information about the availability of rice continously. Application of remote sensing and geographic information system (GIS) technology can support it's information continuously and accurate. In this study, we attempted to identify the rice planting season during El Nino years of 1997, 2006 and 2015 in the Pringsewu district, Lampung and we compared with meteorological drought index. Spatial information of the RPS obtained through Interpretation of multitemporal Landsat data aquired in 1997, 2006 and 2015 using normalized difference vegetation index (NDVI) and the humidity index. While standardized precipitation index (SPI) is used as a indicator of meteorological drought. This study has shown that the application of remote sensing and GIS could accurately monitor the rice planting season during the periods of El Nino in 1997, 2006 and 2015. The fallow land dominated during the El Nino years and there were no significant difference between years. While drought information based on SPI values showed different results between years of El Nino events. In this paper we also discussed the relationship between distribution of fallow land and meteorological drought in a spatial perspective.

By using a new heat budget equation that is closely related to the sea surface temperature (SST) and a dataset from an ocean general circulation model (MOM2) with 10-a integration (1987-1996), the relative importance of various processes determining SST variations in two regions of the Indian Ocean is compared. These regions are defined by the Indian Ocean Dipole Index and will be referred to hereafter as the eastern (0°-10°S, 90°-110°E) and western regions (10°S-10°N, 50°-70°E), respectively. It is shown that in each region there is a falling of SST in boreal summer and a rising in most months of other seasons, but the phases are quite different. In the eastern region, maximum cooling rate occurs in July,whereas in the western region it occurs in June with much larger magnitude. Maximum heating rate occurs in November in the eastern region, but in March in the western one. The western region exhibits another peak of increasing rate of SST in October, indicating a typical half-year period. Net surface heat flux and entrainment show roughly the same phases as the time-varying term, but the former has much larger contribution in most of a year, whereas the latter is important in the boreal summer. Horizontal advection, however, shows completely different seasonal variations as compared with any other terms in the heat budget equation. In the eastern region, it has a maximum in June/November and a minimum in March/September, manifesting a half-year period; in the western region, it reaches the maximum in August and the minimum in November. Further investigation of the horizontal advection indicates that the zonal advection has almost the opposite sign to the meridional advection. In the eastern region, the zonal advection is negative with a peak in August, whereas the meridional one is positive with two peaks in June and October. In the western region, the zonal advection is negative from March to November with two peaks in June and November, whereas the

In a transient accelerated simulation of a coupled climate model, we identified a zonal dipole-like pattern of sea surface temperature (SST) anomalies in the tropical Indian Ocean, which is forced by precessional insolation changes since 300 ka and named as the paleo-IOD (Indian Ocean Dipole). A positive paleo-IOD mean state at 23 kyr precessional band exhibits warmer and wetter conditions over the western Indian Ocean and cooler and drier conditions over the eastern tropical Indian Ocean from August to October. This zonal thermal seesaw at the sea surface can extend downward to the subsurface ocean between 60 and 80 m and accompanies stronger oceanic upwelling in the eastern tropical Indian Ocean. The associated boreal summer-autumn tropospheric circulation anomalies are characterized by anomalous ascent over the western Indian Ocean and anomalous descent over the southeastern tropical Indian Ocean, with anomalous easterlies at the surface along the equatorial Indian Ocean. The positive paleo-IOD largely originates from local air-sea interactions that are induced by the increased summer insolation, and is also contributed by the reduced boreal winter insolation through an oceanic "heat memory effect." Our simulated dipole mode index (DMI) of SST is qualitatively consistent with the paleoceanographic reconstructed DMI based on the UK37 proxy of SST at precessional band and provides a possible explanation for the in-phase precessional variation between boreal winter insolation and the UK37 proxy of SST in the eastern tropical Indian Ocean.

The role of sea surface temperature (SST) anomaly in modulating the terrestrial precipitation in winter around Japan was investigated using a regional atmospheric model. The terrestrial precipitation over the Japan Sea side (JSS) region in northern Japan was sensitive to the offshore SST anomaly through affecting moisture flux toward Japan. Since the offshore SST was clearly warmer in the 2000s relative to the 1980s, the effect of the long-term SST variation on the terrestrial precipitation trend was examined. The experiment with realistic SST simulated the observed trend in terrestrial precipitation in the JSS region. In contrast, the precipitation trend was significantly reduced in the experiment with climatology SST. Therefore, the long-term SST trend is an important factor for the precipitation trend in the region of Japan and the adjacent oceans where SST has significant trends. Precipitation in the Pacific Ocean side of Japan indicated a weak increasing trend even without the SST trend. This suggests that the long-term variations in extra-tropical cyclones are also an important factor for precipitation trends around the Kuroshio extension.

In this paper, the impact of the SST drifts in the ECMWF system 3 forecasting system on the simulated monsoon climatology is investigated. It is shown that hindcasts initialized in February show paradoxically better climatological rainfall in the early monsoon season compared to the hindcasts initialized in the May. The differences in rainfall and SST evolution in the two hindcast sets point to the SST differences as the crucial factor that improves the February initialized hindcasts. Further experiments with the atmospheric component of the ECMWF system 3 forecasting system confirm this by showing similar rainfall biases in the early monsoon season as the hindcasts initialized in the May. This study points to the potential beneficial impacts of reducing systematic biases in the atmospheric components forecasting systems, and of an anomaly initialization technique to improve Indian Monsoon forecasts.

This document is the master work plan for the Resource Conservation and Recovery Act of 1976 (RCRA) Corrective Action Program (RCAP) for single-shell tank (SST) farms at the US. Department of Energy's (DOE'S) Hanford Site. The DOE Office of River Protection (ORP) initiated the RCAP to address the impacts of past and potential future tank waste releases to the environment. This work plan defines RCAP activities for the four SST waste management areas (WMAs) at which releases have contaminated groundwater. Recognizing the potential need for future RCAP activities beyond those specified in this master work plan, DOE has designated the currently planned activities as ''Phase 1.'' If a second phase of activities is needed for the WMAs addressed in Phase 1, or if releases are detected at other SST WMAs, this master work plan will be updated accordingly.

The 1982-1983 El Nino/Southern Oscillation (ENSO) event was accompanied by the largest interannual variation in the Earth's rotation rate on record. In this study we demonstrate that atmospheric forcing was the dominant cause for this rotational anomaly, with atmospheric angular momentum (AAM) integrated from 1000 to 1 mbar (troposphere plus stratosphere) accounting for up to 92% of the interannual variance in the length of day (LOD). Winds between 100 and 1 mbar contributed nearly 20% of the variance explained, indicating that the stratosphere can play a significant role in the Earth's angular momentum budget on interannual time scales. Examination of LOD, AAM, and Southern Oscillation Index (SOI) data for a 15-year span surrounding the 1982-1983 event suggests that the strong rotational response resulted from constructive interference between the low-frequency (approximately 4-6 year) and quasi-biennial (approximately 2-3 year) components of the ENSO phenomenon, as well as the stratospheric Quasi-Biennial Oscillation (QBO). Sources of the remaining LOD discrepancy (approximately 55 and 64 microseconds rms residual for the European Centre for Medium-Range Forecasting (EC) and U.S. National Meteorological Center (NMC) analyses) are explored; noise and systematic errors in the AAM data are estimated to contribute 18 and 33 microseconds, respectively, leaving a residual (rms) of 40 (52) microseconds unaccounted for by the EC (NMC) analysis. Oceanic angular momentum contributions (both moment of inertia changes associated with baroclinic waves and motion terms) are shown to be candidates in closing the interannual axial angular momentum budget.

The numerical simulations, hindcasts and verifications of the tropical Pacific sea surface temperature anomaly (SSTA) have been conducted by using a dynamical tropical Pacific ocean atmosphere coupled model named NCCo. The results showed that the model had performed reasonable simulations of the major El Nino episodes in the history, and the model forecast skill in 1990s had been significantly improved. NCCo model has been used to predict the tropical Pacific SSTA since January 1997. The comparisons between predictions and observations indicated that the occurrence, evolution and ending of the 1997/1998 El Nino episode have been predicted fairly well by using this model. Also, the La Nina episode that began in the autumn of 1998 and the developing tendency of the tropical Pacific SSTA during the year 1999 have been predicted successfully. The forecast skills of NCCo model during the 1997-1999 El Nino and La Nina events are above 0. 5 at 0- 14 lead months.

Highlights: • SST-1 Tokamak PFCs were fabricated using graphite tiles embedded on CuCrZr and CuZr back plates. • PFC cooling is designed considering maximum heat load up to 0.6 MW/m{sup 2}. • Cooling scheme is such that the nucleate boiling will not occur. • The required mass flow rate and velocity for cooling water in each sub-connection are found to be 0.43 kg/s and 5.5 m/s for efficient heat extraction. • The header distribution scheme is modeled using AFT fathom which is in agreement to the required parameters with maximum 5% of deviation. - Abstract: PFC of SST-1 comprising of baffles, divertors and passive stabilizers have been designed and fabricated for a maximum heat load up to 1.0 MW/m{sup 2}. In operational condition, SST-1 divertors and passive stabilizers are expected to operate with a heat load of 0.6 and 0.25 MW/m{sup 2}, respectively. During plasma operation, the heat loads on PFC are required to be removed promptly and efficiently. Thereby the design of an efficient cooling scheme becomes extremely important for an efficient operation of PFC. PFCs are also baked up to 350 °C in order to remove absorbed moistures and other gases. 3D thermal analysis of PFC using ANSYS has been carried out to ensure its thermal stability. The cooling parameters have been calculated according to average incident flux on divertors and passive stabilizers. Engineering design demonstrated the required mass flow rate and velocity for cooling water in each sub-connection are optimized to be 0.43 kg/s and 5.5 m/s for efficient heat extraction under steady state heat load. Maximum temperature which PFC could be maintained is 355 °C and is well within threshold limits of material property degradation. The header distribution, modeled using AFT fathom, resulted for required parameters within maximum 5% of deviation.

The EI Ni(n)o and Southern Oscillation (ENSO) is an interannual phenomenon involved in the tropical Pacific sea-air interactions. In this paper, an asymptotic method of solving nonlinear equations for the ENSO model is proposed. And based on a class of oscillator of the ENSO model and by employing the method of homotopic mapping, the approximate solution of equations for the corresponding ENSO model is studied. It is proved from the results that homotopic method can be used for analysing the sea surface temperature anomaly in the equatorial Pacific of the sea-air oscillator for the ENSO model.

Dengue fever (DF) and dengue hemorrhagic fever (DHF) are growing health concerns throughout Latin America and the Caribbean. This study focuses on Costa Rica, which experienced over 100 000 cases of DF/DHF from 2003 to 2007. We utilized data on sea-surface temperature anomalies related to the El Nino Southern Oscillation (ENSO) and two vegetation indices derived from the Moderate Resolution Imaging Spectrometer (MODIS) from the Terra satellite to model the influence of climate and vegetation dynamics on DF/DHF cases in Costa Rica. Cross-correlations were calculated to evaluate both positive and negative lag effects on the relationships between independent variables and DF/DHF cases. The model, which utilizes a sinusoid and non-linear least squares to fit case data, was able to explain 83% of the variance in weekly DF/DHF cases when independent variables were shifted backwards in time. When the independent variables were shifted forward in time, consistently with a forecasting approach, the model explained 64% of the variance. Importantly, when five ENSO and two vegetation indices were included, the model reproduced a major DF/DHF epidemic of 2005. The unexplained variance in the model may be due to herd immunity and vector control measures, although information regarding these aspects of the disease system are generally lacking. Our analysis suggests that the model may be used to predict DF/DHF outbreaks as early as 40 weeks in advance and may also provide valuable information on the magnitude of future epidemics. In its current form it may be used to inform national vector control programs and policies regarding control measures; it is the first climate-based dengue model developed for this country and is potentially scalable to the broader region of Latin America and the Caribbean where dramatic increases in DF/DHF incidence and spread have been observed.

The Clouds and Earth's Radiant Energy System (CERES) Fast Longwave And SHortwave Radiative Fluxes (FLASHFlux) data products were introduced at the NASA Langley Research Center to address the need of the agricultural, renewable energy management, and science communities for global surface and top-of-atmosphere (TOA) radiative fluxes on a near real-time basis. This has been accomplished by enhancing the speed of CERES processing using simplified calibration and averaging techniques and fast radiation parameterizations to produce fluxes within a week of real-time. While the resulting products are not considered to be sufficiently accurate for studying long-term climate trends, they satisfy the needs for many near real-time scientific data analyses and societal applications. One of the uses of FLASHFlux data is for the evaluation of flux variability and extremes relative to climatological means. Normalizing FLASHFlux TOA fluxes with CERES Energy Balance And Filled (EBAF) TOA fluxes on a global scale, we are able to provide one-year flux change and flux anomalies relative to the EBAF TOA climatology for the "State of the Climate" report (published annually as a BAMS supplement). In this presentation, we extend our analysis to assess the seasonal variability and extremes for most of the year 2015 on a 1-degree regional scale. We also highlight the differences between FLASHFlux surface fluxes compared to the Surface EBAF flux products and assess the feasibility of normalizing the FLASHFLux surface fluxes to surface EBAF to provide surface flux anomalies on a regional scale. Using these anomalies for the TOA and possibly surface fluxes, we assess the radiative flux anomalies of the currently evolving 2015 El Nino on global and regional scales.

Full Text Available Meningoccocal meningitis is a major public health problem that kills thousands annuallyin Africa, Europe, North and South America. Occurrence is, however, highest during thedry seasons in Sahel Africa. Interannual changes in precipitation correlate with interannualchanges in El Nino-Southern Oscillation (ENSO, while interdecadal changes in precipita-tion correlate with Pacific Decadal Oscillation (PDO. The objective of the study was todetermine if there is spectral coherence of seasonal, interannual, and interdecadal changesin occurrence of meningococcal meninigitis in Sahel, Central, and East Africa with interan-nual and interdecadal changes of PDO and ENSO. Time series were fitted to occurrence ofmeningocococcal meningitis in Sahel, Central, and East Africa, to indices of precipitationanomalies in the Sahel, and to indices of ENSO and PDO anomalies. Morlet wavelet wasused to transform the time series to frequency-time domain. Wavelet spectra and coherenceanalyses were performed. Occurrence of meningococcal meningitis showed seasonal, inter-annual, and interdecadal changes. The magnitude of occurrence was higher during warmclimate regime, and strong El Ni nos. Spectra coherence of interannual and interdecadalchanges of ENSO and PDO with occurrence of meningococcal meningitis in Sahel, Central,and East Africa were significant at p < 0.0001. Precipitation in Sahel was low during warmclimate regimes. Spectra coherence of changes in precipitation in Sahel with ENSO wassignificant at p < 0.0001. ENSO and PDO are determinants of the seasonal, interannual,and interdecadal changes in occurrence of meningococcocal meningitis. Public health man-agement of epidemics of meningococcal meningitis should include forecast models of changesin ENSO to predict periods of low precipitation, which initiate occurrence.

This paper synthesizes past events in an attempt to define the general magnitude, duration, and location of large surface solar anomalies over the globe. Surface solar energy values are mostly a function of solar zenith angle, cloud conditions, column atmospheric water vapor, aerosols, and surface albedo. For this study, solar and meteorological parameters for the 10-yr period July 1983 through June 1993 are used. These data were generated as part of the Release 3 Surface meteorology and Solar Energy (SSE) activity under the NASA Earth Science Enterprise (ESE) effort. Release 3 SSE uses upgraded input data and methods relative to previous releases. Cloud conditions are based on recent NASA Version-D International Satellite Cloud Climatology Project (ISCCP) global satellite radiation and cloud data. Meteorological inputs are from Version-I Goddard Earth Observing System (GEOS) reanalysis data that uses both weather station and satellite information. Aerosol transmission for different regions and seasons are for an 'average' year based on historic solar energy data from over 1000 ground sites courtesy of Natural Resources Canada (NRCan). These data are input to a new Langley Parameterized Shortwave Algorithm (LPSA) that calculates surface albedo and surface solar energy. That algorithm is an upgraded version of the 'Staylor' algorithm. Calculations are performed for a 280X280 km equal-area grid system over the globe based on 3-hourly input data. A bi-linear interpolation process is used to estimate data output values on a 1 X 1 degree grid system over the globe. Maximum anomalies are examined relative to El Nino and La Nina events in the tropical Pacific Ocean. Maximum year-to-year anomalies over the globe are provided for a 10-year period. The data may assist in the design of systems with increased reliability. It may also allow for better planning for emergency assistance during some atypical events.

利用菏泽市1981 ～2010年各县区月、年降水资料,对厄尔尼诺年及其次年降水的特征与旱涝灾情进行分析,结果表明,菏泽市年降水量,El Nino年普遍偏少,El Nino次年普遍偏多；不同年份的El Nino事件对菏泽市降水影响不同,1997、2002.年强El Nino事件造成年降水量异常偏少；在El Nino次年中1984、1993、2003年年降水量异常偏多；由于受1987年跨年度El Nino事件影响,1988年年降水量异常偏少；四季降水中,El Nino年的春季无异常；夏、秋、冬季降水普遍偏少,3个季节的30年极小值均出现在El Nino年；El Nino次年四季降水均偏多,春、夏、秋季较明显.El Nino年多旱灾,其次年多涝灾.%The characteristics of precipitation and drought-flood disasters during El Nino events year and the following year were analyzed based on the precipitation measurements in Heze between 1981 to 2010, including monthly and annual data obtained from different counties. The results indicated that the annual precipitation in Here generally decreased in El Nino year and increased in the following year; the influence of El Nino events on Heze precipitation was different in different years, the annual precipitation obviously decreased in 1997 and 2002 when strong El Nino events happened, and yet the annual precipitation obviously increased in the years of 1984, 1993 , and 2003 following El Nino events; the precipitation in spring during El Nino events year and in the following years was as usual, however, the minimal precipitation of summer, autumn, and winter appeared in El Nino years; drought disasters usually happened in El Nino years and more flood disasters in the following years.

We present spectroscopic and imaging observations of apparent ultra-fast spicule-like features observed with CRisp Imaging SpectroPolarimeter (CRISP) at the Swedish 1-m Solar Telescope (SST). The data shows spicules with an apparent velocity above 500 km s-1, very short lifetimes of up to 20 s and length/height around 3500 km. The spicules are seen as dark absorption structures in the Hα wings ±516 mÅ, ±774 mÅ and ±1032 mÅ which suddenly appear and disappear from the FOV. These features show a time delay in their appearance in the blue and red wings by 3-5 s. We suggest that their appearance/disappearance is due to their Doppler motion in and out of the 60 mÅ filter. See Fig. 1 for the evolution of the event at two line positions.

Ellerman bombs are transient brightenings of the extended wings of the solar Balmer lines in emerging active regions. We describe their properties in the ultraviolet lines sampled by the Interface Region Imaging Spectrograph (IRIS), using simultaneous imaging spectroscopy in H$\\alpha$ with the Swedish 1-m Solar Telescope (SST) and ultraviolet images from the Solar Dynamics Observatory for Ellerman bomb detection and identification. We select multiple co-observed Ellerman bombs for detailed analysis. The IRIS spectra strengthen the view that Ellerman bombs mark reconnection between bipolar kilogauss fluxtubes with the reconnection and the resulting bi-directional jet located within the solar photosphere and shielded by overlying chromospheric fibrils in the cores of strong lines. The spectra suggest that the reconnecting photospheric gas underneath is heated sufficiently to momentarily reach stages of ionization normally assigned to the transition region and the corona. We also analyze similar outburst phenome...

To improve the understanding of the single-shell tanks (SSTs) integrity, Washington River Protection Solutions, LLC (WRPS), the USDOE Hanford Site tank contractor, developed an enhanced Single-Shell Tank Integrity Project (SSTIP) in 2009. An expert panel on SST integrity, consisting of various subject matters experts in industry and academia, was created to provide recommendations supporting the development of the project. This panel developed 33 recommendations in four main areas of interest: structural integrity, liner degradation, leak integrity and prevention, and mitigation of contamination migration. In late 2010, seventeen of these recommendations were used to develop the basis for the M-45-10-1 Change Package for the Hanford Federal Agreement and Compliance Order, which is also known as the Tri-Party Agreement.

are proven valuable for quantifying the daily SST cycle in shallow and coastal waters at latitudes 48–60N. Satellite minus in situ observations from moored buoys show biases ranging from −0.3K to 0.1K. A thorough analysis is carried out to obtain the optimal reference field used for calculating the daytime...... temperature anomalies. The best night-time reference field candidate is demonstrated to be an average of 3days of satellite observations from local midnight to 0300. When compared against night-time in situ measurements from various locations, mean biases are found in the order of ±0.1K and standard deviation...

To improve the understanding of the single-shell tanks integrity, Washington River Protection Solutions, LLC, the USDOE Hanford Site tank contractor, developed an enhanced Single-Shell Tank (SST) Integrity Project in 2009. An expert panel on SST integrity, consisting of various subject matters experts in industry and academia, was created to provide recommendations supporting the development of the project. This panel developed 33 recommendations in four main areas of interest: structural integrity, liner degradation, leak integrity and prevention, and mitigation of contamination migration, Seventeen of these recommendations were used to develop the basis for the M-45-10-1 Change Package for the Hanford Federal Agreement and Compliance Order, which is also known as the Tri-Party Agreement. The change package identified two phases of work for SST integrity. The initial phase has been focused on efforts to envelope the integrity of the tanks. The initial phase was divided into two primary areas of investigation: structural integrity and leak integrity. If necessary based on the outcome from the initial work, a second phase would be focused on further definition of the integrity of the concrete and liners. Combined these two phases are designed to support the formal integrity assessment of the Hanford SSTs in 2018 by Independent Qualified Registered Engineer. The work to further define the DOE's understanding of the structural integrity SSTs involves preparing a modern Analysis of Record using a finite element analysis program. Structural analyses of the SSTs have been conducted since 1957, but these analyses used analog calculation, less rigorous models, or focused on individual structures. As such, an integrated understanding of all of the SSTs has not been developed to modern expectations. In support of this effort, other milestones will address the visual inspection of the tank concrete and the collection of concrete core samples from the tanks for analysis

ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) SST-2M is an end-to-end prototype of Small Size class of Telescope for the Cherenkov Telescope Array. It will apply a dual mirror configuration to Imaging Atmospheric Cherenkov Telescopes. The 18 segments composing the primary mirror (diameter 4.3 m) are equipped with an active optics system enabling optical re-alignment during telescope slew. The secondary mirror (diameter 1.8 m) can be moved along three degrees of freedom to perform focus and tilt corrections. We describe the kinematic model used to predict the system performance as well as the hardware and software design solution that will be implemented for optics control.

The study of ring images generated from high-energy muons is a very useful tool for the performance monitoring and calibration of any Imaging Atmosphere Cherenkov Telescope. Isolated muons travelling towards the telescope light collector system produce characteristic Cherenkov ring images in the focal plane camera. Since the geometry and the distribution of light deployed onto the camera can be easily reconstructed analytically for a muon of given energy and direction, muon rings are a powerful tool for monitoring the behaviour of crucial properties of an imaging telescope such as the point-spread-function and the overall light collection efficiency. In this contribution we present the possibility of using the analysis of muon ring images as calibrator for the ASTRI SST-2M prototype point spread function.

The Earth possesses an internal magnetic field (geomagnetic field) generated by convection in the outer core (geodynamo). Previous efforts have been focused along two distinct paths: (1) numerical geodynamo modeling to understand the origin of the geomagnetic field, and the mechanisms of geomagnetic secular variations (SV); and (2) geomagnetic field modeling to map the spatial/temporal variations of the field from geomagnetic data, and to derive core properties, e.g. inversion of core flow near the core-mantle boundary (CMB). Geomagnetic data assimilation is a new approach emerged over the past 5 years: surface observations are assimilated with geodynamo models for better understanding of the core dynamical state, and accurately prediction of SV. In collaboration with several geomagnetic research groups, we have developed the first working geomagnetic data assimilation system, Modular, Scalable, Self-consistent, and Three-dimensional (MoSST) DAS, that includes the MoSST numerical dynamo model; 7000 years of geomagnetic field maps from several field models utilizing satellite and ground observatory data, historical magnetic records and archeo/paleo magnetic data; and an ensemble based optimal interpolation (01) assimilation algorithm. With this system, we have demonstrated clearly that the assimilated core dynamical state is substantially different from those of pure geodynamo simulations. Ensemble assimilation runs also show the convergence of the assimilated solutions inside the core, suggesting that the simulation state is pulled closer to the truth via data assimilation. The forecasts from this system are also very accurate: the 5-year forecast of the geomagnetic field agrees very well with the observations; and the 5-year secular variation forecast is more accurate than the IGRF SV forecast models in the past. Using geomagnetic records up to 2009, we have made an SV forecast for the period from 2010-2015, and is a candidate SV model for IGRF-11.

GRACE is undoubtedly one of the most important sources to observe mass transport on global scales. Numerous applications have shown the validity and impact of using its data. Within the EGSIEM project GRACE gravity field solutions from various processing centers are processed and combined to further increase the spatial and temporal resolution. However, it is expected that GRACE will not continue to observe mass variations from space till its successor GRACE Follow-on will be operational. Thus there is a need for an intermediate technique that will bridge the gap between the two missions and will allow 1) for a continued and uninterrupted time series of mass observations and 2) to compare, crossvalidate and link the two time series. Here we will focus on the combination of high-low satellite-to-satellite tracking (hlSST) of low-Earth orbiting satellites by GNSS in combination with SLR. SLR is known to provide highest quality time-variable gravity for the very low degrees (2-5). HlSST provides a higher spatial resolution but at a lower precision in the very low degrees. Thus it seems natural to combine these two techniques and their benefit has already been demonstrated in the past. Here we make use of the lessons learned within the EGSIEM project and focus on various aspects of combination such as the optimal strategy and relative weighting schemes. We discuss also the achievable spatial and temporal resolutions of different satellite scenarios, such as e.g. using Swarm satellites in combination with Sentinel and/or single GRACE satellites, and present the potential and limitations for geophysical applications.

Solar images from high-resolution, ground-based telescopes are corrected for the blurring effects of atmospheric turbulence by use of adaptive optics and post-facto image restoration. Two classes of image restoration methods are regularly used today, those based on Multi-Frame Blind Deconvolution (MFBD; Löfdahl 2002) and those based on Speckle Interferometry (SI; von der Luhe &Dunn 1987). In a recently started project, we will compare and evaluate such methods for use with spectropolarimetric data from the CRisp Imaging SpectroPolarimeter (CRISP; Scharmer et al. 2008) of the Swedish 1-meter Solar Telescope (SST; Scharmer et al. 2003). For SST/CRISP data we routinely use the Multi-Object MFBD (MOMFBD; van Noort et al. 2005) technique to jointly restore images collected from a wideband camera and from the narrowband cameras behind the CRISP FPI and polarimetry optics. This crucial step in the data reduction pipeline of CRISP (CRISPRED; de la Cruz Rodríguez et al. 2015) is carefully integrated with the application of various procedures that are designed to reduce effects of imperfections in the instruments. In order to make the comparison as fair as possible, we have extended CRISPRED so that the Kiepenheuer-Institut Speckle Interferometry Package (KISIP; Wöger & von der Lühe 2008), together with Speckle Deconvolution (SD; Keller & von der Luehe 1992; Mikurda et al. 2006), can serve as a drop in replacement for MOMFBD. The adaption of SI and SD to CRISPRED will allow us to make fair comparisons not only of the restored images, but also of derivative data like Stokes maps and further on to evaluate the consequences of remaining errors and artifacts for the interpretation of physical quantities inferred through atmospheric model inversions.

A steady state superconducting Tokamak SST-1 is presently under its assembly stage at the Institute for Plasma Research. The SST-1 machine is a family of Superconducting SC coils for both Toroidal field and Poloidal Field. An ultra high vacuum compatible vacuum vessel, placed in the bore of the TF coils, houses the plasma facing components. A high vacuum cryostat encloses all the SC coils and the vacuum vessel. Liquid Nitrogen (LN2) cooled thermal shield between the vacuum vessel & SC coils as well as between cryostat and the SC coils. There are number of crucial cryogenic components as Electrical isolators, 80 K thermal shield, Cryogenic flexible hose etc., which have to be passed the performance validation tests as part of fulfillment of the stringent QA/QC before incorporated in the main assembly. The individual leak tests of components at RT as well as after thermal cycle from 300 K to 77 K ensure us to make final overall leak proof system. These components include, Large numbers of Electrical Isolators for Helium as well as LN2 services, Flexible Bellows and Hoses for Helium as well as LN2 services, Thermal shock tests of large numbers of 80 K Bubble shields In order to validate the helium leak tightness of these components, we have used the calibrated mass spectrometer leak detector (MSLD) at 300 K, 77 K and 4.2. Since it is very difficult to locate the leaks, which are appearing at rather lower temperatures e.g. less than 20 K, We have invented different approaches to resolve the issue of such leaks. This paper, in general describes the design of cryogenic flexible hose, assembly, couplings for leak testing, test method and techniques of thermal cycles test at 77 K inflow conditions and leak testing aspects of different cryogenic components. The test results, the problems encountered and its solutions techniques are discussed.

High-power radio frequency (RF) heating system in the frequency range of ion cyclotron range of frequencies (ICRF) on tokamak needs a mechanism for matching impedance seen by the antenna in presence of plasma to the generator output impedance for maximum transfer of RF power to the plasma with minimum reflections to avoid damage to the generator. The impedance of the antenna is strongly dependent on edge plasma parameters and the impedance sometimes changes as fast as 10{sup −4} s, while the RF generators used can deliver full power only into constant load impedance. Hence, the matching system with dynamic response in between generator and antenna is very much essential for high power ICRF experiments when the plasma is of longer duration with variable load impedance. For ICRF system on SST-1 tokamak, two automatic matching systems are employed each for one transmission line, which consists of motorized stub tuners and phase shifters to match the antenna impedance in the time scale of 120 ms. As a part of initial testing, online impedance matching system is tested with individual transmission lines and then both the lines are matched simultaneously on a variable dummy load which simulates the plasma load. In order to deliver power to both the lines from a single RF generator, hybrid coupler is used which also protects RF generator from reflections up to certain extent. However for hybrid coupler has to work properly and both the lines should see same load impedance. The automatic matching system is installed on tokamak state super-conducting tokamak (SST-1) and is tested up to 140 kW power in the vacuum vessel of the tokamak. Here we present the details of the online matching system and its testing results. The significant result is that we could match the variable load impedance with the generator impedance within 120 ms by suitably adjusting the step counts of the motor controller.

Expression of brain-derived neurotrophic factor (BDNF) and somatostatin (SST) mRNAs in the brain decreases progressively and robustly with age, and lower BDNF and SST expression in the brain has been observed in many brain disorders. BDNF is known to regulate SST expression; however, the mechanisms underlying decreased expression of both genes are not understood. DNA methylation (DNAm) is an attractive candidate mechanism. To investigate the contribution of DNAm to the age-related decline in BDNF and SST expression, the Illumina Infinium HumanMethylation450 Beadchip Array was used to quantify DNAm of BDNF (26 CpG loci) and SST (9 CpG loci) in the orbital frontal cortices of postmortem brains from 22 younger (age 60 years) with known age-dependent BDNF and SST expression differences. Relative to the younger individuals, 10 of the 26 CpG loci in BDNF and 8 of the 9 CpG loci in SST were significantly hypermethylated in the older individuals. DNAm in BDNF exons/promoters I, II, and IV negatively correlated with BDNF expression (r=-0.37, pgenes exhibited similar age-related changes in DNAm and correlation with gene expression. These results suggest that DNAm may be a proximal mechanism for decreased expression of BDNF, SST, and other BDNF- and GABA-related genes with brain aging and, by extension, for brain disorders in which their expression is decreased.

The prediction of the dispersion of air pollutants in urban areas is of great importance to public health, homeland security, and environmental protection. Computational Fluid Dynamics (CFD) emerges as an effective tool for pollutant dispersion modelling. This paper reports and quantitatively validates the shear stress transport (SST) k-ω turbulence closure model and its transitional variant for pollutant dispersion under complex urban environment for the first time. Sensitivity analysis is performed to establish recommendation for the proper use of turbulence models in urban settings. The current SST k-ω simulation is validated rigorously by extensive experimental data using hit rate for velocity components, and the "factor of two" of observations (FAC2) and fractional bias (FB) for concentration field. The simulation results show that current SST k-ω model can predict flow field nicely with an overall hit rate of 0.870, and concentration dispersion with FAC2 = 0.721 and FB = 0.045. The flow simulation of the current SST k-ω model is slightly inferior to that of a detached eddy simulation (DES), but better than that of standard k-ε model. However, the current study is the best among these three model approaches, when validated against measurements of pollutant dispersion in the atmosphere. This work aims to provide recommendation for proper use of CFD to predict pollutant dispersion in urban environment.

The western equatorial Pacific warm pool is characterized by sea surface temperature (SST) higher than 29° C and sea surface salinity (SSS) lower than 35. It is usually considered as a broad oligotrophic region with a nitrate exhausted and low chlorophyll (lower than 0.1 mg m-3 ) surface layer. Nevertheless, ocean colour imagery shows that surface chlorophyll concentrations vary at the interannual, seasonal, and intraseasonal time-scales. In this study, we use the 2000-2007 SeaWiFS data together with QuikScat wind, TMI SST, altimetric sea level, and OSCAR satellite-derived surface currents to describe and understand the variability of the surface chlorophyll in the region. In particular, nutrient and phytoplankton-rich waters upwelled near the country-regionplaceNew Guinea coast influence the distribution of surface chlorophyll in the equatorial warm pool from intra-seasonal to interannual time-scales. We show that the eastern part of the region is occupied by a quasi-persistent strip of very oligotrophic waters with chlorophyll concentrations close to those observed in the subtropical gyres (0.07 mg m-3 ). It extends over about 20 degrees of longitude and its width varies seasonally and with the El Niño/La Niña phases. Overall, this very oligotrophic zone matches n n the well-documented region with the warmest SST (over 30° C), thickest barrier layer (more than 20 m), and highest sea level (more than 220 cm) of the equatorial Pacific. Its eastern limit matches the eastern edge of the warm pool and moves zonally at seasonal and interannual time-scales. While the eastern edge has been described in previous studies, the western edge is poorly known. It is marked by the 0.1 mg m-3 chlorophyll isoline and its zonal motions occur at seasonal, interannual, and intraseasonal time-scales, as well. We investigate the late-2001 to late-2002 time period to assess the intra-seasonal variability of the surface chlorophyll in relation with the wind intra-seasonal variability

Full Text Available The objective of this study was to characterise meteorological droughts in the Central Region of South Africa using Standardised Precipitation Evapotranspiration Index (SPEI and to examine if there is a relationship between drought and El Niño events. The SPEI was used to quantify the precipitation deficit over time and space across the catchment for the time-scales that are important for planning and management of water resources. Based on 12-month time-scale, the total number of drought events identified in the area using SPEI ranged between 13 and 20 during the period of analysis (1952–1999. Considering the effects of event magnitude and duration as severity parameters, the most severe drought event was identified during 1973 followed by 1995 based on 12-month time-scale. Moreover, it was also found that the number of moderate, severe, and extreme drought events identified by SPEI follows increasing trend with decade during the period of analysis. Results of Spearman’s rank correlation test revealed that the trends exhibited by mild (SPEI-3 and SPEI-6, moderate (SPEI-12, severe (SPEI-12, and extreme (SPEI-3 drought categories are statistically significant at 5% significance level. The study also revealed that drought events in the central region of South Africa are preceded by El Niño events in the tropical Pacific (Nino 3.4 with an average lag time of 8 months between the onsets of the two events. It was found that hydrological drought events in the study area lag behind meteorological drought events with an average lag time of 7.4 months. Findings of this study can be used to forecast drought events in the area for the proper planning and management of water resources.

Full Text Available The modern instrumental record (1979–2006 is analyzed in an attempt to reveal the dynamical structure and origins of the major modes of interannual variability of East Asian summer monsoon (EASM and to elucidate their fundamental differences with the major modes of seasonal variability. These differences are instrumental in understanding of the forced (say orbital and internal (say interannual modes of variability in EASM. We show that the leading mode of interannual variation, which accounts for about 39% of the total variance, is primarily associated with decaying phases of major El Nino, whereas the second mode, which accounts for 11.3% of the total variance, is associated with the developing phase of El Nino/La Nina. The EASM responds to ENSO in a nonlinear fashion with regard to the developing and decay phases of El Nino. The two modes are determined by El Nino/La Nina forcing and monsoon-warm ocean interaction, or essentially driven by internal feedback processes within the coupled climate system. For this internal mode, the intertropical convergence zone (ITCZ and subtropical EASM precipitations exhibit an out-of-phase variations; further, the Meiyu in Yangtze River Valley is also out-of-phase with the precipitation in the central North China.

In contrast, the slow and fast annual cycles forced by the solar radiation show an in-phase correlation between the ITCZ and subtropical EASM precipitation. Further, the seasonal march of precipitation displays a continental-scale northward advance of a rain band (that tilts in a southwest-northeastward direction over the entire Indian and East Asian summer monsoon from mid-May toward the end of July. This uniformity in seasonal advance suggests that the position of the northern edge of the summer monsoon or the precipitation over the central North China may be an adequate measure of the monsoon intensity for the forced mode, while the intensity of the internal mode of EASM variability

The strong La Nina of 2010-2011 provided an opportunity to investigate the ecological impacts of El Nino-Southern Oscillation on coastal plankton communities using the nine national reference stations around Australia. Based on remote sensing and across the entire Australian region 2011 (La Nina) was only modestly different from 2010 (El Nino) with the average temperature declining 0.2 percent surface chlorophyll a up 3 percent and modelled primary production down 14 percent. Other changes included a poleward shift in Prochlorococcus and Synechococcus. Along the east coast, there was a reduction in salinity, increase in nutrients, Chlorophytes and Prasinophytes (taxa with chlorophyll b, neoxanthin and prasinoxanthin). The southwest region had a rise in the proportion of 19-hexoyloxyfucoxanthin; possibly coccolithophorids in eddies of the Leeuwin Current and along the sub-tropical front. Pennate diatoms increased, Ceratium spp. decreased and Scrippsiella spp. increased in 2011. Zooplankton biomass declined significantly in 2011. There was a reduction in the abundance of Calocalanus pavo and Temora turbinata and increases in Clausocalanus farrani, Oncaea scottodicarloi and Macrosetella gracilis in 2011. The changes in the plankton community during the strong La Nina of 2011 suggest that this climatic oscillation exacerbates the tropicalization of Australia.

根据1854～1993年期间的El Nino事件资料序列，通过正态性、独立性等统计检验，确定序列的性质。利用Markov随机过程和一阶自回归建立预测模式，给出了下次发生El Nino事件的时间可能在2002年前后。2001年发生的概率为44 %；2002年发生的概率为61 %。%Based on the El Nino event data sequence from 1854 to 1993,the sequence property was determined by using statistical normal and independent test, etc. By using Markov random process and first order auto-regression, we set up the prognostication mode and give the time limit of the occurrence of next El Nino event, which probably occurs around 2002.The occurring probability in 2001 is 44 %,and it is 61 % in 2002.

We have studied the effects of the 2006 El Nino on tropospheric O3 and CO at tropical and sub-tropical latitudes measured from the OMI and MLS instruments on the Aura satellite. The 2006 El Nino-induced drought allowed forest fires set to clear land to burn out of control during October and November in the Indonesian region. The effects of these fires are clearly seen in the enhancement of GO concentration measured from the MLS instrument. We have used a global model of atmospheric chemistry and transport (GMI CTM) to quantify the relative irrrportance of biomass burning and large scale transport: in producing observed changes in tropospheric O3 and CO . The model results show that during October and November both biomass burning and meteorological changes contributed almost equally to the observed increase in tropospheric O3 in the Indonesian region. The biomass component was 4-6 DU but it was limited to the Indonesian region where the fires were most intense, The dynamical component was 4-8 DU but it covered a much larger area in the Indian Ocean extending from South East Asia in the north to western Australia in the south. By December 2006, the effect of biomass taming was reduced to zero and the obsemed changes in tropospheric O3 were mostly due to dynamical effects. The model results show an increase of 2-3% in the global burden of tropospheric ozone. In comparison, the global burdean of CO increased by 8-12%.

In this study, the interannual variability of sea surface temperature (SST) and its atmospheric teleconnection over the western North Pacific (WNP) toward the North Pacific/North America during boreal winter are investigated. First, we defined the WNP mode as the first empirical orthogonal function (EOF) mode of SST anomalies over the WNP region (100-165°E, 0-35°N), of which the principle component time-series are significantly correlated with several well-known climate modes such as the warm pool mode which is the second EOF mode of the tropical to North Pacific SST anomalies, North Pacific oscillation (NPO), North Pacific gyre oscillation (NPGO), and central Pacific (CP)-El Niño at 95% confidence level, but not correlated with the eastern Pacific (EP)-El Niño. The warm phase of the WNP mode (sea surface warming) is initiated by anomalous southerly winds through reduction of wind speed with the background of northerly mean winds over the WNP during boreal winter, i.e., reduced evaporative cooling. Meanwhile, the atmospheric response to the SST warming pattern and its diabatic heating further enhance the southerly wind anomaly, referred to the wind-evaporation-SST (WES) feedback. Thus, the WNP mode is developed and maintained through winter until spring, when the northerly mean wind disappears. Furthermore, it is also known that anomalous upper-level divergence associated with WNP mode leads to the NPO-like structure over the North Pacific and the east-west pressure contrast pattern over the North America through Rossby wave propagation, impacting the climate over the North Pacific and North America.

Translation is an energy-intensive process and tightly regulated. Generally, translation is initiated in a cap-dependent manner. Under stress conditions, typically found within the tumor microenvironment in association with e.g. nutrient deprivation or hypoxia, cap-dependent translation decreases, and alternative modes of translation initiation become more important. Specifically, internal ribosome entry sites (IRES) facilitate translation of specific mRNAs under otherwise translation-inhibitory conditions. This mechanism is controlled by IRES trans-acting factors (ITAF), i.e. by RNA-binding proteins, which interact with and determine the activity of selected IRESs. We aimed at characterizing the translational regulation of the IL-33 decoy receptor sST2, which was enhanced by fibroblast growth factor 2 (FGF2). We identified and verified an IRES within the 5'UTR of sST2. Furthermore, we found that MEK/ERK signaling contributes to FGF2-induced, sST2-IRES activation and translation. Determination of the sST2-5'UTR structure by in-line probing followed by deletion analyses identified 23 nucleotides within the sST2-5'UTR to be required for optimal IRES activity. Finally, we show that the RNA-binding protein heterogeneous ribonucleoprotein A1 (hnRNP A1) binds to the sST2-5'UTR, acts as an ITAF, and thus controls the activity of the sST2-IRES and consequently sST2 translation. Specifically, FGF2 enhances nuclear-cytoplasmic translocation of hnRNP A1, which requires intact MEK/ERK activity. In summary, we provide evidence that the sST2-5'UTR contains an IRES element, which is activated by a MEK/ERK-dependent increase in cytoplasmic localization of hnRNP A1 in response to FGF2, enhancing the translation of sST2.

The labor force is the number of people ages 16 or older who are either working or looking for work. It does not include active-duty military personnel or the institutionalized population, such as prison inmates. Determining the size of the labor force is a way of determining how big the economy can get. The size of the labor force depends on two…

Ten years ago, in 1996, poet and children's book author, Pat Mora began celebrating "book joy" by founding a children's book and reading day, El Dia de los Ninos/El Dia de los Libros or Children's Day/Book Day. Dia is modeled on National Children's Day Celebrations in Mexico held since 1925 when it was launched in conjunction with a…

Ten years ago, in 1996, poet and children's book author, Pat Mora began celebrating "book joy" by founding a children's book and reading day, El Dia de los Ninos/El Dia de los Libros or Children's Day/Book Day. Dia is modeled on National Children's Day Celebrations in Mexico held since 1925 when it was launched in conjunction with a…

Ten years ago, in 1996, poet and children's book author, Pat Mora began celebrating "book joy" by founding a children's book and reading day, El Dia de los Ninos/El Dia de los Libros or Children's Day/Book Day. Dia is modeled on National Children's Day Celebrations in Mexico held since 1925 when it was launched in conjunction with a World…

This paper compares recent spatial anomaly time series of OLR (Outgoing Longwave Radiation) and OLRCLR (Clear Sky OLR) as determined using CERES and AIRS observations over the time period September 2002 through June 2010. We find excellent agreement in OLR anomaly time series of both data sets in almost every detail, down to the 1 x 1 spatial grid point level. This extremely close agreement of OLR anomaly time series derived from observations by two different instruments implies that both sets of results must be highly stable. This agreement also validates to some extent the anomaly time series of the AIRS derived products used in the computation of the AIRS OLR product. The paper then examines anomaly time series of AIRS derived products over the extended time period September 2002 through April 2011. We show that OLR anomalies during this period are closely in phase with those of an El Nino index, and that the recent global and tropical mean decreases in OLR and OLRCLR are a result of a transition from an El Nino condition at the beginning of the data record to La Nina conditions toward the end of the data period. We show that the relationship between global mean, and especially tropical mean, OLR anomalies to the El Nino index can be explained by temporal changes of the distribution of mid-tropospheric water vapor and cloud cover in two spatial regions that are in direct response to El Nino/La Nina activity which occurs outside these spatial regions.

Heavy rainfall associated with a strong El Nino caused over $150 million in landslide damage in the 10-county San Francisco Bay region during the winter and spring of 1998. A team of USGS scientists collected information on landslide locations and damage costs. About $4 million in damages were assessed in San Francisco City and County.

Participants included 106 infants and toddlers living in rural Paraguay and their primary caregiver. Children ranged in age from birth to 24 months and belonged to two distinct groups, including 46 children who had never participated in Pastoral del Nino, an early child development program, and 60 children who had participated in Pastoral for at…

-cloud properties over the period July 1983 to August 1994 suggests that low clouds are statistically related to two processes, (1) GCR and (2) El Nino-Southern Oscillation (ENSO), with GCR explaining a greater percentage of the total variance. Areas where satellites have an unobstructed view of low cloud possess...

Full Text Available Method for El Nino/Southern Oscillation: ENSO by means of wavelet based data compression with appropriate support length of base function is proposed. Through the experiments with observed southern oscillation index, the proposed method is validated. Also a method for determination of appropriate support length is proposed and is validated.